Remove keep clear areas when a view detaches

If a View detaches, its keep clear areas should no longer be considered
when placing a PiP.

Bug: 209577354
Test: atest KeepClearRectsTests#testIgnoreKeepClearRectsFromDetachedViews
Change-Id: I0caa74d4bef2ee157fc3f48747788e30752d09ad
1 file changed