FingerprintManager authentication.

FingerprintDialog.java

fingerprintManager = (FingerprintManager)
    getSystemService(Context.FINGERPRINT_SERVICE);

fingerprintManager.authenticate(
    @Nullable FingerprintManager.CryptoObject cryptoObject,
    @Nullable CancellationSignal cancelSignal,
    0 /* optional flags - should be 0 */, 
    FingerprintManager.AuthenticationCallback callback, 
    @Nullable Handler handler);