private void initCameraPhotoPicker(Bundle savedInstanceState) {
        BoxingConfig config = BoxingManager.getInstance().getBoxingConfig();
        if (config == null || !config.isNeedCamera()) {
            return;
        }
        mCameraPicker = new CameraPickerHelper(savedInstanceState);
        mCameraPicker.setPickCallback(new CameraListener(this));
    }
to clear all medias the first time(the page number is 0). do some clean work.
boxing/src/main/java/com/bilibili/boxing/AbsBoxingViewFragment.java