ticket:9655: Consolidate test code 

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@33193 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9919: Add test to ensure that DateIntervalInfo.setIntervalPattern has no unwanted side effects.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@33194 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9925: CLDR 23 pre-integration part 3, batch 1 (C)

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@33196 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9919: Add check for failure in testSetIntervalPatternNoSideEffect

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@33197 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9919: Add test that DateIntervalFormat.setDateIntervalInfo does not corrup the cache.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@33198 251d0590-4201-4cf1-90de-194747b24ca1