Update IPictureProfileChangedListener comments to indicate flexibility in endpoint

@VintfStability

oneway interface IPictureProfileChangedListener {

    /**

     * Notifies the composer HAL that the picture profile has changed. For picture profile details,

     * check PictureProfile.

     * Notifies the service that the picture profile has changed.

     *

     * @param pictureProfile Picture profile passed to the composer HAL.

     * @param pictureProfile Picture profile that should be cached by the service.

     */

    void onPictureProfileChanged(in PictureProfile pictureProfile);

}