Keyguard Wallet activity can request udfps

- Setup ability to request udfps from a SystemUI activity occluding the
keyguard
- Hookup keyguard wallet activity to request udfps
- Update UdfpsKeyguardView logic so that the udfps icon won't show if
the bouncer is visible. Add check for bouncer visibility to check
whether the bouncer view is visible - sometimes the bouncer expansion
can report visible even though the view itself is not visibile.

Test: atest SystemUITest
Bug: 183024921

Change-Id: I2aa922149586a8a6319e884442c21b74607e5017