Merge "Correct documentation for update()"

     * it must process all but the tag length and buffer the possible tag data for processing during

     * finish().

     *

     * @param input Data to be processed.  Note that update() may or may not consume all of the data

     *        provided.  See return value.

     * @param input Data to be processed.  update() must consume all input data.

     *

     * @param authToken Authentication token. Can be nullable if not provided.

     *