Group previewMargin with previewWidth etc.

Author: yawnoc

app/src/main/java/io/github/yawnoc/strokeinput/InputContainer.java

@@ -682,7 +682,6 @@ private void updateKeyPreview() {
 
     final int previewWidth = keyPreview.width;
     final int previewHeight = keyPreview.height;
-    
     final int previewMargin = activeKey.previewMargin;
 
     final int keyboardLeftX = 0;