message: Add regex validation for ManagedClusterAgentPoolProfile.name
diff: "properties": {
  "name": {
  "type": "string",
  - "description": "Unique name of the agent pool profile in the context of the subscription and resource group."
  + "description": "Unique name of the agent pool profile in the context of the subscription and resource group.",
  + "pattern": "^[a-z][a-z0-9]{0,11}$"
  },
  "count": {
  "type": "integer",
  