Fix CoordinatorLayout anchor gravity handling

CoordinatorLayout would position anchored child views in the wrong place
when using some layout_gravity/layout_anchorGravity settings. Clarify
the responsibility of each gravity handling step - anchor vs. child.

Bug 21282731

Change-Id: I053c6c40802da19e5a7002b6b853413a4d2ee0cc
1 file changed