public void setShowCropOverlay(boolean showCropOverlay) {
    if (mShowCropOverlay != showCropOverlay) {
      mShowCropOverlay = showCropOverlay;
      setCropOverlayVisibility();
    }
  }
if to show crop overlay UI what contains the crop window UI surrounded by background over the
cropping image.<br>
default: true, may disable for animation or frame transition.
core/src/main/java/com/theartofdev/edmodo/cropper/CropImageView.java