Update active group when showing BiometricPrompt

When authenticating after recently switching between work/owner profiles,
the active group is incorrect. This was fixed for keyguard. Now it's fixed
for BiometricPrompt as well.

Bug: 122582871

Test: 1) Flash wipe device
      2) Enroll FP in owner profile
      3) Set up testDPC using instructions in b/123502937 comment #1
      4) Enroll a work profile finger
      5) Install biometric prompt demo app
      6) Open owner profile version of app, show biometric prompt
      at this point, non-work background should be shown, and
      owner profile's fingerprint should be accepted

Change-Id: I429a703ad98f420de36b691fb740aabc08471e56