Use AUTH_SCRIMMED_SHADE if transitioning to shade

Since the end scrim state should be SHADE, we want
to make sure the notification scrim doesn't
suddenly become transparent.

Test: atest SystemUITests
Test: manually test with sensitive notifications
not allowed to show on LS, pull down notification
shade with UDFPS enrolled
Fixes: 213158348

Change-Id: I367e5769edd82f9f5651d7522bdbfacbe7967786