ticket:8464: Add more to mock API.

git-svn-id: http://source.icu-project.org/repos/icu/icu4j/branches/tkeep@34205 251d0590-4201-4cf1-90de-194747b24ca1
ticket:8464: Add more to mock API.

git-svn-id: http://source.icu-project.org/repos/icu/icu4j/branches/tkeep@34206 251d0590-4201-4cf1-90de-194747b24ca1
ticket:8464: Merge r34074 to r34206 from trunk.

git-svn-id: http://source.icu-project.org/repos/icu/icu4j/branches/tkeep@34207 251d0590-4201-4cf1-90de-194747b24ca1