Add alt auth affordance for keyguard notif-taps

The alternative auth view still allows touches to bring up the bouncer;
however touches should never be sent to child views.

When highlighting the fp:
- show bg protection circle behind fp
- use scrim with opacity .66

Additionally dump udfps animation information on SystemUI dumpsys

Test: atest UdfpsKeyguardViewControllerTest UdfpsControllerTest
Test: manual - setup udfps, tap on notification on LS or from locked
shade, see highlight on udfps icon
Bug: 175717712

Change-Id: I5f02573ccf7523d1b83aa997b8e986ab01e97a43