Added getter for session Id to AudioSink

Added a method to expose the audio session id at AudioSink interface
so that the AudioPlayer in stagefright can retrieve it.

Also:
- Fixed audio effect send level not being initialized in mediaplayer.
- Fixed compilation error when LOGV is enabled in mediaplayer JNI

Change-Id: I4bb55454fd63d646e0e677692d737c4843fb05fb
diff --git a/media/libmediaplayerservice/MediaPlayerService.h b/media/libmediaplayerservice/MediaPlayerService.h
index a967ee2..4492e20 100644
--- a/media/libmediaplayerservice/MediaPlayerService.h
+++ b/media/libmediaplayerservice/MediaPlayerService.h
@@ -77,6 +77,7 @@
         virtual uint32_t        latency() const;
         virtual float           msecsPerFrame() const;
         virtual status_t        getPosition(uint32_t *position);
+        virtual int             getSessionId();
 
         virtual status_t        open(
                 uint32_t sampleRate, int channelCount,
@@ -133,6 +134,7 @@
         virtual uint32_t        latency() const;
         virtual float           msecsPerFrame() const;
         virtual status_t        getPosition(uint32_t *position);
+        virtual int             getSessionId();
 
         virtual status_t        open(
                 uint32_t sampleRate, int channelCount, int format,