Set channel mask when opening audio sink

Update the code to use the AudioSink::open() interface that
 takes a channel mask as an additional parameter. The code
 is only stereo, and returns an error when attempting to create
 a video editor audio sink with more than two channels.

Change-Id: Ib9bba067da0b286c08656976b89fba7c8b42f99f
diff --git a/libvideoeditor/lvpp/VideoEditorPlayer.h b/libvideoeditor/lvpp/VideoEditorPlayer.h
index 88a2aeb..34f9bc5 100755
--- a/libvideoeditor/lvpp/VideoEditorPlayer.h
+++ b/libvideoeditor/lvpp/VideoEditorPlayer.h
@@ -49,7 +49,7 @@
         virtual int             getSessionId();
 
         virtual status_t        open(
-                uint32_t sampleRate, int channelCount,
+                uint32_t sampleRate, int channelCount, audio_channel_mask_t channelMask,
                 audio_format_t format, int bufferCount,
                 AudioCallback cb, void *cookie);