@Override
  protected void applyTtlUpdate(MessageInfo remoteBlob, RemoteReplicaInfo remoteReplicaInfo) {
    throw new UnsupportedOperationException("applyTtlUpdate is unsupported");
  }
This method checks if permanent blob from remote on-prem server is permanent in local-store
@param remoteBlob the {@link MessageInfo} that will be transformed into a TTL update
@param remoteReplicaInfo The remote replica that is being replicated from
ambry-replication/src/main/java/com/github/ambry/replication/BackupCheckerThread.java