[BUG] Cognitive account's networkInjection definition is not correct

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/6c548b0bd279f5e233661b1c81fb5b61b19965cd/specification/cognitiveservices/resource-manager/Microsoft.CognitiveServices/preview/2025-04-01-preview/cognitiveservices.json#L8813

### API Spec version

2025-04-01-preview

### Describe the bug

In the API spec, the `networkInjection` should be an object. But the API requires it to be an array of objects.

### Expected behavior

The API should be consistent with the API spec.

### Actual behavior

In the API spec, the `networkInjection` should be an object. But the API requires it to be an array of objects.

### Reproduction Steps

#####

11:47:55 PUT management.azure.com /subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.CognitiveServices/accounts/ai-sandbox-reference-deployment-02?api-version=2025-04-01-preview 400

Request

| Header | Value |
| ----- | ----- |
| Authorization | REDACTED |
| Content-Length | 551 |
| Content-Type | application/json |
| User-Agent | HashiCorp Terraform/1.12.2 (+https://www.terraform.io) terraform-provider-azapi/dev pid-222c6c49-1b0a-5959-a213-6608f9eb8820 |
| X-Ms-Correlation-Request-Id | 57c2aa64-9a39-c52f-4108-599195419968 |
| Accept | application/json |

Request Body:
```json
{
"identity": {
"type": "SystemAssigned"
},
"kind": "AIServices",
"location": "eastus",
"properties": {
"customSubDomainName": "ai-sandbox-reference-deployment-02",
"disableLocalAuth": false,
"networkAcls": {
"defaultAction": "Allow",
"ipRules": [],
"virtualNetworkRules": []
},
"networkInjections": {
"scenario": "agent",
"subnetArmId": "/subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.Network/virtualNetworks/vnet-henglu77/subnets/Subnet-1",
"useMicrosoftManagedNetwork": false
},
"publicNetworkAccess": "Disabled"
},
"sku": {
"name": "S0"
}
}
```

Response

**Response Status: 400 Bad Request**

| Header | Value |
| ----- | ----- |
| X-Ms-Correlation-Request-Id | 57c2aa64-9a39-c52f-4108-599195419968 |
| X-Ms-Operation-Identifier | appId=06e00f79-5059-418e-9648-f60a13302591,tenantId=213e87ed-8e08-4eb4-a63c-c073058f7b00,objectId=d1132398-0f30-4db5-89bb-899b3cea92df/southeastasia/35571edb-c0b4-4a64-a96f-3d762a7625fe |
| Content-Length | 779 |
| Expires | -1 |
| X-Envoy-Upstream-Service-Time | 34 |
| X-Ms-Ratelimit-Remaining-Subscription-Global-Writes | 2999 |
| X-Ms-Routing-Request-Id | SOUTHEASTASIA:20250707T034755Z:0d0c06e2-c529-428f-9021-e3405d3df9bd |
| Content-Type | application/json; charset=utf-8 |
| Date | Mon, 07 Jul 2025 03:47:54 GMT |
| Pragma | no-cache |
| X-Content-Type-Options | nosniff |
| X-Ms-Ratelimit-Remaining-Subscription-Writes | 199 |
| X-Ms-Request-Id | dc855a03-54d2-495f-b7f1-edfdc06850d8 |
| Cache-Control | no-cache |
| Strict-Transport-Security | max-age=31536000; includeSubDomains |
| X-Cache | CONFIG_NOCACHE |
| X-Msedge-Ref | Ref A: 826D3949C3DC4646BC53BD37AE7F5E04 Ref B: MAA201060515023 Ref C: 2025-07-07T03:47:48Z |

Response Body:
```json
{
"error": {
"code": "InvalidResourceProperties",
"message": "The 'properties' field is invalid, error: 'Cannot deserialize the current JSON object (e.g. {\"name\":\"value\"}) into type 'System.Collections.Generic.List`1[Microsoft.CognitiveServices.ResourceProvider.Contracts.NetworkInjection]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.\nTo fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List\u003cT\u003e) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.\nPath 'networkInjections.scenario'.'."
}
}
```

-----

#####

11:50:30 PUT management.azure.com /subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.CognitiveServices/accounts/ai-sandbox-reference-deployment-03?api-version=2025-04-01-preview 201

Request

| Header | Value |
| ----- | ----- |
| Accept | application/json |
| Authorization | REDACTED |
| Content-Length | 553 |
| Content-Type | application/json |
| User-Agent | HashiCorp Terraform/1.12.2 (+https://www.terraform.io) terraform-provider-azapi/dev pid-222c6c49-1b0a-5959-a213-6608f9eb8820 |
| X-Ms-Correlation-Request-Id | 28773e90-1396-47b3-2f3a-0047f3f15d0c |

Request Body:
```json
{
"identity": {
"type": "SystemAssigned"
},
"kind": "AIServices",
"location": "eastus",
"properties": {
"customSubDomainName": "ai-sandbox-reference-deployment-03",
"disableLocalAuth": false,
"networkAcls": {
"defaultAction": "Allow",
"ipRules": [],
"virtualNetworkRules": []
},
"networkInjections": [
{
"scenario": "agent",
"subnetArmId": "/subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.Network/virtualNetworks/vnet-henglu77/subnets/Subnet-1",
"useMicrosoftManagedNetwork": false
}
],
"publicNetworkAccess": "Disabled"
},
"sku": {
"name": "S0"
}
}
```

Response

**Response Status: 201 Created**

| Header | Value |
| ----- | ----- |
| Pragma | no-cache |
| Strict-Transport-Security | max-age=31536000; includeSubDomains |
| X-Cache | CONFIG_NOCACHE |
| X-Envoy-Upstream-Service-Time | 6529 |
| Cache-Control | no-cache |
| Content-Type | application/json; charset=utf-8 |
| X-Ms-Request-Id | c39268e5-4aff-41cd-92d1-a13ac4ddf407 |
| X-Ms-Routing-Request-Id | SOUTHEASTASIA:20250707T035030Z:34a3bb8b-08b7-45ba-804f-06e8fd0c499d |
| X-Msedge-Ref | Ref A: 997D9C65F0EB4F6C8357C65BB28FFF6E Ref B: MAA201060516009 Ref C: 2025-07-07T03:50:19Z |
| Date | Mon, 07 Jul 2025 03:50:29 GMT |
| Etag | "1300f0f2-0000-0100-0000-686b44050000" |
| Expires | -1 |
| X-Ms-Correlation-Request-Id | 28773e90-1396-47b3-2f3a-0047f3f15d0c |
| X-Ms-Ratelimit-Remaining-Subscription-Writes | 199 |
| Content-Length | 34354 |
| X-Content-Type-Options | nosniff |
| X-Ms-Operation-Identifier | appId=06e00f79-5059-418e-9648-f60a13302591,tenantId=213e87ed-8e08-4eb4-a63c-c073058f7b00,objectId=d1132398-0f30-4db5-89bb-899b3cea92df/southeastasia/8c849c19-c452-4e05-88a6-b80af1ed4680 |
| X-Ms-Ratelimit-Remaining-Subscription-Global-Writes | 2999 |

Response Body:
```json
{
"etag": "\"1300f0f2-0000-0100-0000-686b44050000\"",
"id": "/subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.CognitiveServices/accounts/ai-sandbox-reference-deployment-03",
"identity": {
"principalId": "d5c053cd-7650-47ea-aac6-4da58cd9453a",
"tenantId": "213e87ed-8e08-4eb4-a63c-c073058f7b00",
"type": "SystemAssigned"
},
"kind": "AIServices",
"location": "eastus",
"name": "ai-sandbox-reference-deployment-03",
"properties": {
"allowProjectManagement": false,
"apiProperties": {
"qnaAzureSearchEndpointKey": null
},
"customSubDomainName": "ai-sandbox-reference-deployment-03",
"dateCreated": "2025-07-07T03:50:25.3900958Z",
"disableLocalAuth": false,
"endpoint": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"endpoints": {
"AI Foundry API": "https://ai-sandbox-reference-deployment-03.services.ai.azure.com/",
"Azure AI Model Inference API": "https://ai-sandbox-reference-deployment-03.services.ai.azure.com/",
"Cohere AI API": "https://ai-sandbox-reference-deployment-03.services.ai.azure.com/",
"Computer Vision": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Container": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Content Safety": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Content Understanding": "https://ai-sandbox-reference-deployment-03.services.ai.azure.com/",
"Conversational Language Understanding Authoring": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"ConversationalLURuntime": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Custom Question Answering": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Custom Question Answering Authoring": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Custom Text Authoring": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"CustomTranslator": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"DocumentTranslation": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"FormRecognizer": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"LUIS": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Language": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Mistral AI API": "https://ai-sandbox-reference-deployment-03.services.ai.azure.com/",
"OpenAI Dall-E API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Language Model Instance API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Model Scaleset API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Moderations API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Realtime API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Sora API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"OpenAI Whisper API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"QnAMaker": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"QuestionAnswering": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Audio Content Creation": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Batch Avatar": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Batch Text to Speech": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Custom Avatar": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Custom Voice": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Custom Voice Trial": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speaker Identification": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speaker Verification": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speech to Text": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speech to Text (Standard)": "https://eastus.stt.speech.microsoft.com",
"Speech Services Speech to Text 2024-05-15-preview": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speech to Text 2024-11-15": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speech to Text v3.2": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Speech to Text v3.2_internal.1": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Speech Services Text to Speech (Neural)": "https://eastus.tts.speech.microsoft.com",
"Text Analytics": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"TextTranslation": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"TextTranslation-Global": "https://api.cognitive.microsofttranslator.com/",
"Token": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Token Service API": "https://ai-sandbox-reference-deployment-03.openai.azure.com/",
"Turing": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Video Translation": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Voice Agent Realtime API": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/",
"Voice Live Realtime API": "https://ai-sandbox-reference-deployment-03.cognitiveservices.azure.com/"
},
"internalId": "4da1ecafe8b14062b074366776936ea2",
"isMigrated": false,
"networkAcls": {
"defaultAction": "Allow",
"ipRules": [],
"virtualNetworkRules": []
},
"networkInjections": [
{
"scenario": "agent",
"subnetArmId": "/subscriptions/00000/resourceGroups/henglu77/providers/Microsoft.Network/virtualNetworks/vnet-henglu77/subnets/Subnet-1",
"useMicrosoftManagedNetwork": false
}
],
"privateEndpointConnections": [],
"provisioningState": "Creating",
"publicNetworkAccess": "Disabled"
},
"sku": {
"name": "S0"
},
"systemData": {
"createdAt": "2025-07-07T03:50:21.6648091Z",
"createdBy": "06e00f79-5059-418e-9648-f60a13302591",
"createdByType": "Application",
"lastModifiedAt": "2025-07-07T03:50:21.6648091Z",
"lastModifiedBy": "06e00f79-5059-418e-9648-f60a13302591",
"lastModifiedByType": "Application"
},
"type": "Microsoft.CognitiveServices/accounts"
}
```

-----

### Environment

_No response_

Start at the linked cognitiveservices.json definition around line 8813 and compare its networkInjections shape with the successful and failed request bodies in this issue. Confirm the intended array-versus-object contract for API version 2025-04-01-preview, then update the specification so it matches the service behavior and validate the generated API definition.

Written by the indexing model from the issue text.