Make BiometricPrompt credential UI closer to Settings

Adjusts the fonts, sizes, and positions of the AuthCredentialView UI
invoked by BiometricPrompt to better match the UI for setting or
confirming a PIN/pattern/password in Settings.

Test: Manually, using the BiometricPrompt demo and TestDPC apps

Fixes: 152053691
Change-Id: I0d0316b2ac5bde696706e916a29021481e824509