Merge "Update documentation for TV messages" into udc-dev

     * detected from the stream based on whether or not they are enabled by

     * {@link #setTvMessageEnabled(int, int, TvMessageEventType, boolean)}.

     *

     * This queue is expected to already contain the message data before calling

     * {@link android.hardware.tv.input.ITvInputCallback#notifyTvMessageEvent}.

     * The HAL implementation is expected to have already created the queue

     * before the notification callback is called for the first time.

     *

     * @param deviceId The ID of the device that contains the stream to get the queue for.

     * @param streamId THe ID of the stream to get the queue for.

     * @return The descriptor of the TV message queue.

     * the device that sent the message should be contained in

     * {@link android.hardware.tv.input.TvMessage#groupId}

     *

     * Invoking this callback for the first time immediately triggers

     * {@link android.hardware.tv.input.ITvInput#getTvMessageQueueDesc}. It is

     * expected for the queue to be ready with

     * the relevant messages for the event before this callback is called.

     *

     * @param event Event passed to the client.

     */

    void notifyTvMessageEvent(in TvMessageEvent event);