@Override
  public void addListener(VcrClusterParticipantListener listener) {
    listeners.add(listener);
  }
Register {@link DeprecatedContainerCloudSyncTask}s to sync deleted container information from account service to
VCR.

@param engine the {@link StateMachineEngine} to register the task state model.
ambry-cloud/src/main/java/com/github/ambry/cloud/HelixVcrClusterParticipant.java