View: Remove tooltip callbacks when detached from window

When a View has tooltip text set, every hover event will fire a callback
to hide the tooltip after a 15 second timeout. Since the callback holds
a reference to the View, it will leak the View for that duration after
the Activity is finished or the View is removed.

Prevent this temporary leak by removing the tooltip callbacks
immediately when the View is detatched from the window.

Bug: 281473769
Test: manual, heap dump using Android Studio
Change-Id: I9044759be0feaf094aa4c140565dfa015b944bd8
Merged-In: I9044759be0feaf094aa4c140565dfa015b944bd8