Adding device-idle policy time to alarms

Adding device-idle policy time to alarms to denote the earliest time
they can fire based on device_idle.
Alarm dispatch order now ensures that idle-until alarms go out first, as
alarms pending while idling now go along with the idle-until alarm in
the same batch.

Allow-while-idle alarms are now rescheduled because of idle before
arming the kernel timer, which means they should no longer cause
unnecessary wakeups.

Test: atest FrameworksMockingServicesTests:com.android.server.alarm

Bug: 170279979
Bug: 158795479
Change-Id: I36dc298a15e55e405ea3468b7872436648d71684