Error when instantiating a subclass in x-ms-examples: Discriminator value "latency" not found

Hi,

I've been trying everything I could to figure out why "instantiating" a new instance of the discriminating schema didn't work for me. The below is my schema and x-ms-examples:

```json
"ipControl": {
"type": "object",
"description": "The control object that mutates the TCP traffic",
"discriminator": "controlType",
"properties": {
"controlType": {
"type": "string",
"enum": [
"latency",
"bandwidth",
"https",
"qos"
]
}
},
"required": [
"controlType"
]
},
...
"latency": {
"type": "object",
"description": "Model that represents the IP Latency Control",
"allOf": [
{
"$ref": "#/definitions/ipControl"
}
],
"properties": {
"delayMilliseconds": {
"type": "integer",
"description": "The latency in milliseconds"
},
"delaySigma": {
"type": "integer",
"description": "The latency sigma in milliseconds"
},
"correlationPercent": {
"type": "number",
"description": "the percentage of correlation"
},
"distribution": {
"type": "string",
"description": "The distribution of the latency"
}
},
"required": [
"delayMilliseconds",
"delaySigma",
"correlationPercent",
"distribution"
]
},
```

Usage in `x-ms-examples`:
```
"responses": {
"200": {
"headers": {},
"body": {
"id": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/exampleRG/providers/Microsoft.Moxy/vnetInterceptorConfigurations/exampleInterceptorConfig",
"type": "Microsoft.Moxy/vnetInterceptorConfigurations",
"name": "exampleInterceptorConfig",
"location": "westus2",
"properties": {
"routes": [
{
"name": "exampleRoute",
"priority": 1,
"destination": "10.140.1.2:8080",
"ipControls": [
{
"controlType": "latency",
"delayMilliseconds": 850,
"delaySigma": "100",
"correlationPercent": 10,
"distribution": "normal"
}
]
}
],
"provisioningState": "Succeeded"
},
...
```

When I ran the `oav validate-example` command, I get the following error:

> {
code: 'DISCRIMINATOR_VALUE_NOT_FOUND',
message: 'Discriminator value "latency" not found',
schemaUrl: 'types\\vnetInterceptorConfiguration.json',
exampleUrl: 'examples\\vnetInterceptorConfigurations\\CreateOrUpdateVnetInterceptorConfiguration.json',
schemaPosition: { line: 242, column: 18 },
schemaJsonPath: '#/discriminatorMap',
examplePosition: { line: 82, column: 34 },
exampleJsonPath: '$responses.201.body.properties.routes[0].ipControls[0].controlType',
severity: 0,
source: 'response',
operationId: 'VnetInterceptorConfiguration_CreateOrUpdate',
level: '\u001b[31merror\u001b[39m'
}

I wonder if anyone hit the same problem? Any help would be greatly appreciated!