Track pid for each session

so they can be properly freed.

Change-Id: I6f389035bc29e74e7c367c1c6d0252b180f666b3
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index dfc2066..fd86737 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -141,8 +141,8 @@
     static uint32_t getInputFramesLost(audio_io_handle_t ioHandle);
 
     static int newAudioSessionId();
-    static void acquireAudioSessionId(int audioSession);
-    static void releaseAudioSessionId(int audioSession);
+    static void acquireAudioSessionId(int audioSession, pid_t pid);
+    static void releaseAudioSessionId(int audioSession, pid_t pid);
 
     // types of io configuration change events received with ioConfigChanged()
     enum io_config_event {