Revert "avcenc: Prepend startcodes to output buffers"

This reverts commit 0519467b5906f760da14a0583593293f7610fb3a.
Revert "Fixed a 'setVideoSurfaceTexture failed(-22)' after reset."

This reverts commit 42a57cd25b71f739010cb1385cd51b0487187023.
Revert "Add ThreadedSource to Stagefright framework"

This reverts commit d259ff36359eba47f4737e48e02aafb64d54af1f.