Move wifi check into systemUI

Rather than checking if the phone is connected to a wifi network at
notification receipt (and choosing whether to hide sensitive content
based on that), we will instead check at notification render time. We
also will combine the "last locked time check" with the "has the device
been locked for 10 minutes" check, so that a notification doesn't show
as unredacted, and then become redacted 10 minutes later

Bug: 358403414
Fixes: 393600031
Flag: android.app.redact_sensitive_content_notifications_on_lockscreen
Test: atest
NotificationManagerServiceTest,NotificationLockscreenUserManagerTest

Change-Id: Ib36e1bb2a7e4cbdf7d594e2762c33ecf9d66bd49