Camera: Lazy load sound files to speed up camera startup

Lazy loading of sound files can speed up camera startup more than 60ms,
it gives users a great experience. Many apps do not playSound when camera
open or they may use their own audio files. so we load audio files as needed.

Bug: 128432959
Test: install wechat app,open camera,use systrace to see the uiThread wait time.
Change-Id: I3b3697cf9d0d919b88276f6d8e7fdd84578f4fcd
diff --git a/services/camera/libcameraservice/CameraService.h b/services/camera/libcameraservice/CameraService.h
index 624d1ca..991c770 100644
--- a/services/camera/libcameraservice/CameraService.h
+++ b/services/camera/libcameraservice/CameraService.h
@@ -177,10 +177,10 @@
         NUM_SOUNDS
     };
 
-    void                loadSound();
     void                playSound(sound_kind kind);
-    void                releaseSound();
-
+    void                loadSoundLocked(sound_kind kind);
+    void                decreaseSoundRef();
+    void                increaseSoundRef();
     /**
      * Update the state of a given camera device (open/close/active/idle) with
      * the camera proxy service in the system service