修改裁剪窗口默认背景颜色

- CropCanvasView背景设为蓝色
- ZoomContainerView背景设为黄色

gallery/src/main/java/cc/winboll/studio/gallery/ZoomContainerView.java

@@ -38,6 +38,7 @@ public class ZoomContainerView extends FrameLayout {
     
     private void init() {
         setWillNotDraw(false);
+        setBackgroundColor(Color.YELLOW);
         
         borderPaint = new Paint();
         borderPaint.setColor(Color.parseColor("#333333"));