examples/mediaplayer: Allow to select audio from /rom/* for easy test
examples/mediaplayer: Allow to select audio from /rom/* for easy test

With this patch, we can just download ROMFS to update audio resource
files for testing, without any code change/building.

jeongchanKim/TizenRT,an4967/TizenRT,an4967/TizenRT,chanijjani/TizenRT,pillip8282/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,davidfather/TizenRT,jsdosa/TizenRT,junmin-kim/TizenRT,junmin-kim/TizenRT,jsdosa/TizenRT,pillip8282/TizenRT,davidfather/TizenRT,Samsung/TizenRT,davidfather/TizenRT,chanijjani/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,chanijjani/TizenRT,junmin-kim/TizenRT,Samsung/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,junmin-kim/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,Samsung/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,sunghan-chang/TizenRT,an4967/TizenRT,davidfather/TizenRT,jeongarmy/TizenRT,junmin-kim/TizenRT,Samsung/TizenRT,jeongarmy/TizenRT,jsdosa/TizenRT,davidfather/TizenRT,chanijjani/TizenRT,chanijjani/TizenRT,Samsung/TizenRT,jeongchanKim/TizenRT,jsdosa/TizenRT,chanijjani/TizenRT,jsdosa/TizenRT,sunghan-chang/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,jeongchanKim/TizenRT,davidfather/TizenRT,junmin-kim/TizenRT,an4967/TizenRT,pillip8282/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,davidfather/TizenRT,pillip8282/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,chanijjani/TizenRT,jeongarmy/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,sunghan-chang/TizenRT,jeongchanKim/TizenRT