AOD: Fix broken triggers after failed prox check

Fixes an issue where after a failed prox check
we would not correctly reset mPulsePending and
thus never trigger a pulse again until the
DozeService restarts.

Also adds logging for dropped and canceled pulses
to aid diagnosing similar or different bugs
in the future.

Also adds a regression test.

Fixes: 37477968
Test: runtest -x /frameworks/base/packages/SystemUI/tests/src/com/android/systemui/doze/DozeTriggersTest.java
Change-Id: Ic465b7686ae1937a29d07a66fe44cf7ad18419ef