[BUG] "Microsoft.Maintenance/configurationAssignments@2021-09-01-preview" location is not returned in GET response

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/main/specification/maintenance/resource-manager/Microsoft.Maintenance/preview/2021-09-01-preview/Maintenance.json#L1910

### API Spec version

2021-09-01-preview

### Describe the bug

The field "location" is not returned in GET reponse

```
GET /subscriptions/000/resourceGroups/henglu425main/providers/Microsoft.Compute/virtualMachines/henglu425main/providers/Microsoft.Maintenance/configurationAssign
ments/henglu425main

{
"id": "/subscriptions/000/resourceGroups/henglu425main/providers/Microsoft.Compute/virtualMachines/henglu425main/providers/Microsoft.Maintenance/configurationAssign
ments/henglu425main",
"name": "henglu425main",
"properties": {
"maintenanceConfigurationId": "/subscriptions/000/resourcegroups/henglu425main/providers/microsoft.maintenance/maintenanceconfigurations/henglu425main",
"resourceId": "/subscriptions/000/resourcegroups/henglu425main/providers/microsoft.compute/virtualmachines/henglu425main"
},
"type": "Microsoft.Maintenance/configurationAssignments"
}
```

### Expected behavior

The `location` field should be returned in GET response

### Actual behavior

The `location` field is not returned in GET response

### Reproduction Steps

1. Create a "Microsoft.Maintenance/configurationAssignments@2021-09-01-preview" and set location in the create request.
2. Call GET request and check the location in response.

### Environment

_No response_

Start with specification/maintenance/resource-manager/Microsoft.Maintenance/preview/2021-09-01-preview/Maintenance.json at line 1910 and compare the configurationAssignments schema with the behavior described in the issue. Reproduce the create-then-GET request for API version 2021-09-01-preview; done means the GET response includes the location field.

Written by the indexing model from the issue text.