Use audio_policy_output_flags_t consistently

This affects:
 - IAudioFlinger::openOutput
 - AudioTrack::AudioTrack
 - AudioTrack::set
 - apps that call these

Change-Id: I26fb281bac6cb87593d17697bc9cb37a835af205
diff --git a/media/libmedia/ToneGenerator.cpp b/media/libmedia/ToneGenerator.cpp
index 54eb98a..9c3170c 100644
--- a/media/libmedia/ToneGenerator.cpp
+++ b/media/libmedia/ToneGenerator.cpp
@@ -1024,7 +1024,7 @@
                       AUDIO_FORMAT_PCM_16_BIT,
                       AUDIO_CHANNEL_OUT_MONO,
                       0,
-                      0,
+                      AUDIO_POLICY_OUTPUT_FLAG_NONE,
                       audioCallback,
                       this,
                       0,