Reverts the change which adds a gesture detector in
TextView for detecting clicks on ClickableSpans. A click
is considered MotionEvent.ACTION_UP. Revert needed because
the singleTapUp refactoring has a potential to break
existing apps.
Bug: 23692690
Test: attached in the same topic
Change-Id: Ife47fd0608480130123091bc60a7e9dd1efe8785