frameworks/base: Changes related to DASH

Creating Extended MediaPlayerListener and Native MediaPlayer
for DASH.

Squashed the below changes

frameworks/base : Handling usecases for ext mediaplayer
Change-Id: Ic5242161bf30bd2688bd6aba6d6115ab0768e963

frameworks/base: media: Add support for extended file types
Change-Id: I0b3654dee776dc70f0fc3f32e9fe8eca4f4faa8e

Change-Id: Ief49777e94b818851052715d6dbd9e51982da85a