[DO NOT MERGE] Transition to clear state after gesture cancelation.

The agreed-upon behavior has always been that after gesture cancelation, touch explorer would exist in essentially a dead state.
It should not be possible to execute a two-finger passthrough gesture for example after doing an invalid gesture.
This is likely why we see GESTURE_PASSTHROUGH in cases where we expect GESTURE_UNKNOWN.
Fix: 171421786
Bug: 162521649
Test: manual
Change-Id: Idce921c5278dea174ec5dad5cecf046f12ab113d

Change-Id: Ic71246adc613ea60d3f25974e4085814c4b3211d