Add missing serialVersionUIDs

Change-Id: I827716a83bfcfb241949551c29c60c6ca54e8b13

java/com/google/gitiles/GitilesRequestFailureException.java

diff --git a/java/com/google/gitiles/GitilesRequestFailureException.java b/java/com/google/gitiles/GitilesRequestFailureException.java
index 91f9cf8..316c023 100644
--- a/java/com/google/gitiles/GitilesRequestFailureException.java
+++ b/java/com/google/gitiles/GitilesRequestFailureException.java
@@ -87,6 +87,7 @@
  * MyErrorHandlingFilter} will handle that. You can control how the error should be surfaced.
  */
 public final class GitilesRequestFailureException extends RuntimeException {
+  private static final long serialVersionUID = 1L;
   private final FailureReason reason;
   private String publicErrorMessage;
 

javatests/com/google/gitiles/DefaultErrorHandlingFilterTest.java

diff --git a/javatests/com/google/gitiles/DefaultErrorHandlingFilterTest.java b/javatests/com/google/gitiles/DefaultErrorHandlingFilterTest.java
index 6832658..b96e43d 100644
--- a/javatests/com/google/gitiles/DefaultErrorHandlingFilterTest.java
+++ b/javatests/com/google/gitiles/DefaultErrorHandlingFilterTest.java
@@ -35,6 +35,8 @@
   }
 
   private static class TestServlet extends HttpServlet {
+    private static final long serialVersionUID = 1L;
+
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse res) {
       throw new GitilesRequestFailureException(FailureReason.INCORECT_PARAMETER);