don't set glview transparent, it many cause afterimage (cocos2d#20298)

Author: minggo

cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxActivity.java

@@ -300,7 +300,8 @@ public void init() {
     public Cocos2dxGLSurfaceView onCreateView() {
         Cocos2dxGLSurfaceView glSurfaceView = new Cocos2dxGLSurfaceView(this);
         //this line is need on some device if we specify an alpha bits
-        if(this.mGLContextAttrs[3] > 0) glSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
+        // FIXME: is it needed? And it will cause afterimage.
+        // if(this.mGLContextAttrs[3] > 0) glSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
 
         // use custom EGLConfigureChooser
         Cocos2dxEGLConfigChooser chooser = new Cocos2dxEGLConfigChooser(this.mGLContextAttrs);