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.cpp b/media/libmediaplayerservice/MediaPlayerService.cpp
index d975cb9..c43e9bb 100644
--- a/media/libmediaplayerservice/MediaPlayerService.cpp
+++ b/media/libmediaplayerservice/MediaPlayerService.cpp
@@ -1546,6 +1546,11 @@
 
 }
 
+int MediaPlayerService::AudioOutput::getSessionId()
+{
+    return mSessionId;
+}
+
 #undef LOG_TAG
 #define LOG_TAG "AudioCache"
 MediaPlayerService::AudioCache::AudioCache(const char* name) :
@@ -1733,4 +1738,9 @@
     p->mSignal.signal();
 }
 
+int MediaPlayerService::AudioCache::getSessionId()
+{
+    return 0;
+}
+
 } // namespace android