av: audioflinger: reduce duplicate code

reduce duplicate code

Test: TH
Bug: 260145070

Change-Id: I0d3600fc27ed64d6331222715ca5c3ee56e64c6a
Merged-In: I0d3600fc27ed64d6331222715ca5c3ee56e64c6a
Signed-off-by: SPeak Shen <speakshen@163.com>
diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index 6a138bb..33983d7 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -310,6 +310,7 @@
         binder::Status unmute(/*out*/ bool *ret) override;
     private:
         Track* const mTrack;
+        bool setMute(bool muted);
     };
     sp<AudioVibrationController> mAudioVibrationController;
     sp<os::ExternalVibration>    mExternalVibration;