Hide overlay windows when requesting media projection permission.

1: Cherry-pick ag/4067454 - Setting PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS
updateNonSystemOverlayWindowsVisibilityIfNeeded on relayoutWindow

2: Cherry-pick ag/3650369 - If PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS changed on
relayoutWindow() then updateNonSystemOverlayWindowsVisibilityIfNeeded

3: Add permissions to SystemUI to allow it to hide non-system overlays

Bug: 34170870
Test: manual (see bug for poc)
Change-Id: I57cb0f390d9a78e721c5ddce49a377d385002753
Merged-In: I57cb0f390d9a78e721c5ddce49a377d385002753