Root cause: the test case has timezone dependency, it need to set
timezone before run the test case or it will be failed on different
timezone.
Solution: Replace AlarmManager.setTimeZone with TimeZone.setDefault,
AlarmManager.setTimeZone() seems failed to change timezone for test case.
Fix: 333857349
Test: http://ab/I51500010265016400
Change-Id: Id36dd10866720cba19cce471d294e09272c8091f