Add some unit tests for listener exact alarms

Listener exact alarms no longer require permission. Adding unit test
cases to document and test the same.

Added couple string translations that were missing for exact-allow
reasons.

Test: FrameworksMockingServicesTests:AlarmManagerServiceTest

BYPASS_INCLUSIVE_LANGUAGE_REASON=existing code

Fixes: 265838027
Change-Id: I0b985b5ee381bf8385e9ed43fa6efb4460bf59e6