Media item data model

MediaItem definition follow Android standard definition from MediaBrowser.

Key	ValueType	Value
description	string
flag	int	(FLAG_BROWSABLE:1, FLAG_PLAYABLE:2)
icon_bitmap	string
icon_uri	string
media_id	string
media_type	long	BT_FOLDER_TYPE_ALBUMS BT_FOLDER_TYPE_ARTISTS BT_FOLDER_TYPE_GENRES BT_FOLDER_TYPE_MIXED BT_FOLDER_TYPE_PLAYLISTS BT_FOLDER_TYPE_TITLES BT_FOLDER_TYPE_YEARS EXTRA_BT_FOLDER_TYPE
media_uri	string
subtitle	string
title	string