HIVE-8299: HiveServer2 in http-kerberos & doAs=true is failing with org.apache.hadoop.security.AccessControlException (Vaibhav Gumashta reviewed by Thejas Nair)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1628821 13f79535-47bb-0310-9956-ffa450edef68