Run HOVER_EXIT event only if there's no BUTTON_PRESS event after.

When a mouse click happens, a HOVER_EXIT prceeds a BUTTON_PRESS
MotionEvent. This ends up causing the menu to fade away. We will check
for whether there's a BUTTON_PRESS event immediately afterward, and only
run hideMenu() after a certain timeout.

Bug: 160245414
Test: Clicking on items on the PIP menu works again
Change-Id: If06e9b51d2fa47735472f48314a9d5b4b146157b