Merge "Challenge is expected in timestamp token in case 2"

     *

     *   o The HMAC field must validate correctly.

     *

     *   o The challenge field in the auth token must contain the challenge value contained in the

     *     BeginResult returned from IKeyMintDevice::begin().

     *   o The challenge field in the timestamp token must contain the challenge value contained in

     *     the BeginResult returned from IKeyMintDevice::begin().

     *

     * The resulting secure time value is then used to authenticate the HardwareAuthToken. For the

     * auth token to be valid, all of the following has to be true:

     *

     *   o The key must have a Tag::USER_AUTH_TYPE that matches the auth type in the token.

     *

     *   o The challenge field in the auth token must contain the challenge value contained in the

     *     BeginResult returned from IKeyMintDevice::begin().

     *

     *   o The timestamp in the auth token plus the value of the Tag::AUTH_TIMEOUT must be greater

     *     than the provided secure timestamp.