Messaging: Remove unnecessary toString() and String.valueOf() calls

Change-Id: I5d5624386ba72b9e7074a7da909f78baaee73f75

src/com/android/messaging/sms/MmsUtils.java

@@ -137,7 +137,7 @@ public class MmsUtils {
             case MMS_REQUEST_NO_RETRY:
                 return "NO_RETRY";
             default:
-                return String.valueOf(status) + " (check MmsUtils)";
+                return status + " (check MmsUtils)";
         }
     }