Fix serialVersionUID warning in ViewFilterTest

Change-Id: Ie747e88d8b45f6534f92b992b3466a6326125d9a

gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java

diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
index 1088692..712ddf5 100644
--- a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
@@ -384,8 +384,14 @@
     } else {
       req.setPathInfo(pathAndQuery);
     }
-    new MetaServlet(mf){}.service(req, new FakeHttpServletResponse());
+    dummyServlet(mf).service(req, new FakeHttpServletResponse());
 
     return view.get();
   }
+
+  private MetaServlet dummyServlet(MetaFilter mf) {
+    return new MetaServlet(mf) {
+      private static final long serialVersionUID = 1L;
+    };
+  }
 }