Do not dismiss BiometricPrompt when "soft" errors are received

Some errors such as ERROR_TIMEOUT should not caues the BiometricPrompt
dialog to be dismissed. Updated plumbing to allow
onBiometricAuthenticated to pass a string indicating the failure reason

Fixes: 131240917

Test: BiometricPromptDemo
Change-Id: I63a6f1138a24fbc3736184efefc620dd5bb640dd