Show fingerprint icon when face fails on BiometricPrompt

When BiometricPrompt is launched with both a face and fingerprint
enrolled, ensure that the fingerprint icon is shown immediately after
face authentication fails. This replaces the old behavior where an error
icon would be shown for ~2 seconds after face authentication failed.

Test: Manual:
1. Enroll both fingerprint and face on a device
2. Trigger BiometricPrompt (e.g. Internet > Settings > Share)
3. Ensure face authentication fails (e.g. by not looking at device)
4. Verify that the fingerprint icon is shown immediately

Fixes: 195794375
Change-Id: I5abf788df5e973711d932af685e674f03e89fae6