Make Volley use normal String concatenation in ImageLoader.java

The java compiler will make this a StringBuilder if it needs to be.

Clover/app/src/main/java/com/android/volley/toolbox/ImageLoader.java

@@ -474,7 +474,6 @@ public class ImageLoader {
      * @param maxHeight The max-height of the output.
      */
     private static String getCacheKey(String url, int maxWidth, int maxHeight) {
-        return new StringBuilder(url.length() + 12).append("#W").append(maxWidth)
-                .append("#H").append(maxHeight).append(url).toString();
+        return "#W" + maxWidth + "#H" + maxHeight + url;
     }
 }