Log a bit to differentiate PendingIntent and callback alarms

Before this change, only PendingIntent alarms were tracked for scheduling.
Add a boolean is_listener field in the atom so we can know if an alarm
scheduled is with PendingIntent or an IAlarmListener.

Test: atest FrameworksMockingServicesTests:AlarmManagerServiceTest
Test: atest CtsStatsdAtomHostTestCases:AlarmStatsTest


Flag: EXEMPT metrics only change

Bug: 274001514
Change-Id: Ied8beacff47c5b3efaa6285a0c2f119fe167c166