Delay gesture processing in FalsingCollector.

Clicks are processed after a delay on views. To handle this, we can't
immediately analyze gestures in the FalsingManager. Instead, delay
processing slightly to give click handlers an opportunity to
acknowledge gestures.

Fixes: 184963035
Test: manual
Change-Id: I2c98d20c76b8fda1f53a0b4a3ec29674c32aa550