Merge "AudioFormatDescription: remove docs about encapsulation"

     *   - Otherwise, "x-" prefix is added, e.g. "audio/x-iec61937".

     *   - All MIME types not found in the IANA formats list have an associated

     *     comment.

     *

     * For PCM encapsulations with a known bitstream format, the latter

     * is added to the encapsulation encoding as a suffix, after a "+" char.

     * For example, an IEC61937 encapsulation of AC3 has the following

     * representation:

     *   type = NON_PCM,

     *   pcm = PcmType.INT_16_BIT,

     *   encoding = "audio/x-iec61937+audio/ac3"

     */

    @utf8InCpp String encoding;

}