base

Don't crash when canceling alarms if a direct listener is present

If a direct listener alarm attempts to match a regular
PendingIntent alarm, it will attempt to fetch the binder of the
regular alarm's direct listener, which is null, and crash the
system with an NPE.

Bug: 25823676
Change-Id: I85fb98b43436930a2513274dc5ab408f7d41d97f