AudioFlinger: move utilities files to library

Test: Compiles, atest AudioTrackTest AudioRecordTest
Bug: 284179393
Change-Id: I10c2c08e10422dd498eeb10a75a935430c0ad3df
diff --git a/services/audioflinger/FastMixer.h b/services/audioflinger/FastMixer.h
index d71519f..9847507 100644
--- a/services/audioflinger/FastMixer.h
+++ b/services/audioflinger/FastMixer.h
@@ -23,7 +23,7 @@
 #include "StateQueue.h"
 #include "FastMixerState.h"
 #include "FastMixerDumpState.h"
-#include "NBAIO_Tee.h"
+#include <afutils/NBAIO_Tee.h>
 
 namespace android {