message: Make NIC VM readOnly
diff: "properties": {
  "virtualMachine": {
  "$ref": "./network.json#/definitions/SubResource",
  - "description": "The reference of a virtual machine."
  + "description": "The reference of a virtual machine.",
  + "readOnly": true
  },
  "networkSecurityGroup": {
  "$ref": "./networkSecurityGroup.json#/definitions/NetworkSecurityGroup",
  