Update notes for submitted changes

* libstagefright: Fix intermittent pause during tunnel A-V playback
* libstagefright: print seek statistics even when paused
* stagefright: add rendering statistics
* libstagefright: Filewrite in seperate thread for single video track
* stagefright: add an extra buffer to ANW's BUfferQueue
* Revert "frameworks/av: rendering statistics for Stagefright."