[automerger skipped] Merge "Use abstractions to allow FullscreenUserSwitcher take advantage of SystemUIOverlayWindow." into rvc-dev am: 995e2de8 am: 6def2baf -s ours am: 12556209 -s ours am: 97017d92 -s ours
am skip reason: Change-Id I19825da81f8d1b1259a2ba115e0238a9ffa69e37 with SHA-1 84590ea2 is in history

Change-Id: I46d862a29f845d1d5cb2997a27ba58d8b1b2ff8c