The implication of auth-conf is not followed in optimized HDFS data transfer encryption

HDFS-6606 provided an optimized way of HDFS data transfer encryption. The optimized encryption is build on top of SASL wrap/unwrap when auth-conf is configured.

When user specifies auth-conf, he wants both integrity and confidential. While the current implementation of the optimization implements only confidential with AES/CTR and there is no integrity grantees, which means the implications of auth-conf were not strictly followed.