PulsingGestureListen only checks taps when pulsing

We don't want to unnecessarily make requests to the
falsing manager unless we're about to handle the touch.

Test: manually tap/longpress the lock screen empty space
and observe we never see the "Tap again to open" falsing
help message
Test: atest PulsingGestureListenerTest
Fixes: 244659326
Bug: 242125976

Change-Id: Idb29d5dafe6d03ceb1f7b6ea468475e5be054618