[Media TTT] Hide the chip if the user taps the screen.

This CL defines a generic gesture detector class since we now have
multiple cases where we want to detect gestures across the whole
display.

Still TODO: Don't hide the chip if the user taps the chip itself.

Bug: 214274529
Bug: 211487971
Test: manual: verify tapping the screen hides the chip
Test: atest GenericGestureDetectorTest
Test: atest media.taptotransfer
Change-Id: I3951d0bbb3a04d5b82a54339a548b4e293bbf527