Enable per-use user authenticated keys to be used.

This makes symmetric Cipher and Mac implementations backed by
AndroidKeyStore succeed in their initialization when the key is
configured to require user authentication for every use. Users
of such keys should obtain an instance of Cipher or Mac, initialize
it with the key, and then authorize the operation by passing this
Cipher or Mac instance to FingerprintManager.authenticate.

Bug: 18088752
Change-Id: Ia15a1e5f8274c3623f665dae1f400ff539639ab1