add isDynamic method in MediaPlayer

Created by: Ligverd

Add method isDynamic in MediaPlayer or tell me how to know the type static/dynamic?

thank you.

...
function MediaPlayer() {
...
function isDynamic() {
        if (!playbackInitialized) {
            throw PLAYBACK_NOT_INITIALIZED_ERROR;
        }
        return playbackController.getIsDynamic();
}
...
instance = {
...
isDynamic: isDynamic,
...