YARN-1698. Fixed default TimelineStore in code to match what is documented in yarn-default.xml. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1566937 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1566938 13f79535-47bb-0310-9956-ffa450edef68