Adjust ConfirmDeviceCredentialActivity system bars

CDCA is a transparent activity with the sole purpose of
requesting authentication. Since authentication is all drawn
by SystemUI, we should also stop this activity from drawing
the StatusBar.

Register to receive biometric system events (early user canceled),
so that we can finish() and start the activity transition
simultaneously. This fixes some navigation bar jank.

Bug: 148273355

Test: Set up a work profile, then install BiometricPromptDemo
      Disable one-lock and set up a password/biometric for the
      work profile. Lock/unlock screen, then open the work
      profile version of the app. No status bar jank seen.
Change-Id: I54a352527ed007dcaf1bea14a51711e4022fe028