Audio streaming error when playing a stream that contains "end of file".

Although EOS is being post from Myhandler.h file upon receipt of BYE message from RTSP
server. This happens because the Nuplayer::Renderer::onDrainAudioQueue() funtion
returns false after mAudioSink->getPosition() call , and the EOS message present in
mAudioQueue was lost.
The mAudioSink->getPosition() returns NO_INIT as mAudioSink->open() is not yet called,
hence no audio track exists in MediaPlayerService::AudioOutput.

Change-Id: I90d76943d3c10986171da3bc85a2a931af79ad30
Author: Gurudatta Bhakte <gurudattax.bhakte@intel.com>
Signed-off-by: Gurudatta Bhakte <gurudattax.bhakte@intel.com>
Singed-off-by: Shuo Gao <shuo.gao@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Author-tracking-BZ: 24194