Add modality switch callback to update UDFPS layout during configuration changes.

Addresses a race condition when the view is attached and the modality switch is in progress.

Also fixes an issue with the confirmation button being re-enabled after a configuration change.

Bug: 190832486
Test: atest AuthBiometricFaceToFingerprintViewTest
Change-Id: I701d9d6f03474df2dda6f48e506208ddf7eab2c3