Allow crypto + credential auth with BiometricPrompt

Removes the explicit check and error thrown when calling
BiometricPrompt.authenticate(CryptoObject) after enabling device
credential authentication for the prompt.

Test: Allow device credential, call authenticate(CryptoObject)
Fixes: 147693375
Change-Id: I8d0e5a7297ad07a45c59fde1989a25ccb6ec72c5