Requery silent notifs lockscreen setting on change

Fixes: 226586443
Test: manual
  1. Settings > Notifications > Notification on lock screen > Show all
  2. Receive a silent notification
  3. Lock device
  4. Verify silent notification visible on lockscreen
Test: atest KeyguardNotificationVisibilityProviderTest

Change-Id: I4a0b8b2985cb3a1c7b3d5c8e5176122aa8627440