HIVE-7890 - SessionState creates HMS Client while not impersonating (Brock reviewed by Prasad)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1622288 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7682 - HadoopThriftAuthBridge20S should not reset configuration unless required (Brock reviewed by Prasad)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1622289 13f79535-47bb-0310-9956-ffa450edef68