Re-land "Use SOURCE_CLASS_POINTER as the default source for MotionEvent"

This reverts commit 3ccd2488c53139368d4153cdcf925e0f90cdd158.

Reason for revert: Blocking issues have been addressed,
ready to reland. See bug.

Bug: 213425347

Change-Id: I91a29949f87a0d27188b323bf302400ee19e964d
2 files changed