Use symbolic constants from <system/audio.h>

AUDIO_INTERLEAVE_*
AUDIO_STREAM_MIN
AUDIO_SESSION_ALLOCATE

Change-Id: I31dd6f327204685e50716079ce21c4ba206dff11
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index e046e03..c3c9033 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1133,7 +1133,7 @@
 
     // mStreamTypes[AUDIO_STREAM_CNT] is initialized by stream_type_t default constructor
     // There is no AUDIO_STREAM_MIN, and ++ operator does not compile
-    for (audio_stream_type_t stream = (audio_stream_type_t) 0; stream < AUDIO_STREAM_CNT;
+    for (audio_stream_type_t stream = AUDIO_STREAM_MIN; stream < AUDIO_STREAM_CNT;
             stream = (audio_stream_type_t) (stream + 1)) {
         mStreamTypes[stream].volume = mAudioFlinger->streamVolume_l(stream);
         mStreamTypes[stream].mute = mAudioFlinger->streamMute_l(stream);