YARN-1924. Made ZKRMStateStore updateApplication(Attempt)StateInternal work when Application(Attempt) state hasn't been stored before. Contributed by Jian He.
svn merge --ignore-ancestry -c 1586547 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1586548 13f79535-47bb-0310-9956-ffa450edef68