clean up default fingerprint HIDL@2.1 implementation

- remove Binder dependency by passing keystore token to onAuthenticated()
- move notify() to cpp file

Test: recovers from killing keystore, fingerprint unlocks device,
FingerprintDialog works with crypto objects.

Fixes bug 34264028

Change-Id: Ic0de31603f4bc4147d6faf014af89e787b1ef244