message: Mark id/kind/type fields as readOnly
  Mark id/kind/type fields as readOnly to make "AutoRest --azure-validator
  openapi-type=arm" happy.
diff: },
  "id": {
  "type": "string",
  - "description": "The id of the created account"
  + "description": "The id of the created account",
  + "readOnly": true
  },
  "kind": {
  "type": "string",
  },
  "name": {
  "type": "string",
  - "description": "The name of the created account"
  + "description": "The name of the created account",
  + "readOnly": true
  },
  "properties": {
  "x-ms-client-flatten": true,
  },
  "type": {
  "type": "string",
  - "description": "Resource type"
  + "description": "Resource type",
  + "readOnly": true
  }
  },
  "x-ms-azure-resource": true
  