HADOOP-9444. Modify hadoop-policy.xml to replace unexpanded variables to a default value of '*'. Contributed by Roman Shaposhnik.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1462417 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9235-trunk-gd