Hide non-system overlay window on ActivityPicker am: c55b5b54d2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/17628098

Change-Id: I5404085011ef8f1120e0a8239e4049d617716690
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>