Use symbolic constants from <system/audio.h>

AUDIO_INTERLEAVE_*
AUDIO_STREAM_MIN
AUDIO_SESSION_ALLOCATE

Change-Id: I31dd6f327204685e50716079ce21c4ba206dff11
diff --git a/media/libmedia/ToneGenerator.cpp b/media/libmedia/ToneGenerator.cpp
index adef3be..61b6d36 100644
--- a/media/libmedia/ToneGenerator.cpp
+++ b/media/libmedia/ToneGenerator.cpp
@@ -1057,7 +1057,7 @@
                       0,    // notificationFrames
                       0,    // sharedBuffer
                       mThreadCanCallJava,
-                      0,    // sessionId
+                      AUDIO_SESSION_ALLOCATE,
                       AudioTrack::TRANSFER_CALLBACK);
 
     if (mpAudioTrack->initCheck() != NO_ERROR) {