Copy the list before passing to deliverAlarms

Downstream code from deliverAlarmsLocked can cause removeLocked or
removeImpl to be called which changes the size of the list.

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

Bug: 175701084
Change-Id: I5228c323bb9698864c467e9e4c400459ca404b3c
Merged-In: I5228c323bb9698864c467e9e4c400459ca404b3c