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/libmedia/mediaplayer.cpp b/media/libmedia/mediaplayer.cpp
index c6b2efb..cc41e66 100644
--- a/media/libmedia/mediaplayer.cpp
+++ b/media/libmedia/mediaplayer.cpp
@@ -56,6 +56,7 @@
     mVideoWidth = mVideoHeight = 0;
     mLockThreadId = 0;
     mAudioSessionId = AudioSystem::newAudioSessionId();
+    mSendLevel = 0;
 }
 
 MediaPlayer::~MediaPlayer()