@Override
  String getStateModelName() {
    return LeaderStandbySMD.name;
  }
Create and return an instance of {@link LeaderStandbyHelixVcrStateModel}
@param resourceName the resource name for which this state model is being created.
@param partitionName the partition name for which this state model is being created.

@return an instance of {@link LeaderStandbyHelixVcrStateModel}.
ambry-cloud/src/main/java/com/github/ambry/cloud/LeaderStandbyHelixVcrStateModelFactory.java