"gatewaySetting" is serialized incorrectly inside "connectionParameterSets"

### Severity

P2 - High (Major functionality broken)

### Describe the Bug with repro steps

## Expected Behavior

When a selected parameter set contains `gatewaySetting`, LogicAppsUX should serialize it using the gateway-compatible `connectionParameters` shape, or the gateway connection API should accept the `connectionParametersSet` representation.

## Actual Behavior

A custom connector using `connectionParameterSets` cannot create an on-premises gateway connection because the selected gateway parameters are serialized as `connectionParametersSet` values.

## Reproduction

Define a parameter set containing `authType` and `gatewaySetting`:

```json
{
"name": "gateway-noauth",
"uiDefinition": {
"displayName": "Gateway",
"description": "Connect through the on-premises gateway."
},
"parameters": {
"authType": {
"type": "string",
"uiDefinition": {
"displayName": "Authentication Type",
"description": "No authentication",
"constraints": {
"required": "true",
"allowedValues": [
{
"text": "No authentication",
"value": "anonymous"
}
]
}
}
},
"gateway": {
"type": "gatewaySetting",
"gatewaySettings": {
"dataSourceType": "CustomConnector",
"connectionDetails": []
},
"uiDefinition": {
"displayName": "Gateway",
"description": "Select a gateway.",
"constraints": {
"required": "true",
"capability": ["gateway"]
}
}
}
}
}
```

## Actual Payload

LogicAppsUX submits:

```json
{
"properties": {
"connectionParametersSet": {
"name": "gateway-noauth",
"values": {
"authType": {
"value": "anonymous"
},
"gateway": {
"value": {
"id": "/providers/Microsoft.PowerApps/gatewayClusters/"
}
}
}
}
}
}
```

The request fails with:

```text
The 'authType' connection parameter is null or invalid for the on-premise connection request.
```

## Working Payload

The Power Platform custom connector wizard creates successful gateway connections using:

```json
{
"properties": {
"connectionParameters": {
"authType": "anonymous",
"gateway": {
"id": "/providers/Microsoft.PowerApps/gatewayClusters/"
}
}
}
}
```

## Relevant Code

```text
libs/designer-v2/src/lib/ui/panel/connectionsPanel/createConnection/createConnectionInternal.tsx
```

The current parameter-set serializer wraps every parameter in a `value` object:

```ts
values: Object.fromEntries(
Object.keys(filteredParameterValues).map((key) => [
key,
{ value: filteredParameterValues[key] },
])
)
```

This serialization is incompatible with the gateway connection API's expected flat `connectionParameters` contract.

### What type of Logic App Is this happening in?

Standard (Portal)

### Are you experiencing a regression?

_No response_

### Which operating system are you using?

Windows

### Did you refer to the TSG before filing this issue? https://aka.ms/lauxtsg

Yes

### Workflow JSON

```json

```

### Screenshots or Videos

_No response_

### Environment

- Microsoft Power Automate
- Custom connector deployed with `paconn`
- Microsoft on-premises data gateway, standard mode

### Additional context

_No response_