Back-port fixes for b/62196835

Bug: 62196835
Test: Created an accessibility service that displays a system
and a toast overlay, confirmed that it disappeared when we
reached the accessibility permission screen that uses this
flag.

Change-Id: Ic51ead670fc480e549512ba1d02f49d9c13bc3f0
(cherry picked from commit d4a5fd1ce32b25c8a8d7af35c4676011d64faa22)
7 files changed