This streamlines the exception throwing logic for per-op auth keys of AndroidKeyStore. Change-Id: I7e27c17fd89d5a7f71f5d7578f584189c5236fb8
Bug: 18088752 Change-Id: I027f9530a02cca081aae8eb94833d2fdcb678e9a
AES and HmacSHA256 symmetric keys can now be imported into AndroidKeyStore. These keys cannot yet be used. Bug: 18088752 Change-Id: Iad2fd49d15ac4c2d676abe1153f5b5f0b6ff496c