Fix selection crash in GestureSelectionHelper MotionEvent handling.

Pull in this changes from ag/4276105.

Fixes: 79945297
Test: atest GestureSelectionHelperTest and manual

Change-Id: Ia132f7fcc1093e160f285d9ad3e35c0986d3ff81
Merged-In: Ia132f7fcc1093e160f285d9ad3e35c0986d3ff81
2 files changed