Add proto extension for Wrr LB to pretty printing code.

Author: kannanjgithub

xds/src/main/java/io/grpc/xds/MessagePrinter.java

@@ -32,6 +32,7 @@
 import io.envoyproxy.envoy.extensions.filters.http.rbac.v3.RBACPerRoute;
 import io.envoyproxy.envoy.extensions.filters.http.router.v3.Router;
 import io.envoyproxy.envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager;
+import io.envoyproxy.envoy.extensions.load_balancing_policies.wrr_locality.v3.WrrLocality;
 import io.envoyproxy.envoy.extensions.transport_sockets.tls.v3.DownstreamTlsContext;
 import io.envoyproxy.envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext;
 import io.grpc.xds.client.MessagePrettyPrinter;
@@ -52,7 +53,7 @@ private static class LazyHolder {
     private static JsonFormat.Printer newPrinter() {
       TypeRegistry.Builder registry =
           TypeRegistry.newBuilder()
-              .add(Listener.getDescriptor())
+              .addmak(Listener.getDescriptor())
               .add(HttpConnectionManager.getDescriptor())
               .add(HTTPFault.getDescriptor())
               .add(RBAC.getDescriptor())
@@ -65,7 +66,8 @@ private static JsonFormat.Printer newPrinter() {
               .add(RouteConfiguration.getDescriptor())
               .add(Cluster.getDescriptor())
               .add(ClusterConfig.getDescriptor())
-              .add(ClusterLoadAssignment.getDescriptor());
+              .add(ClusterLoadAssignment.getDescriptor())
+              .add(WrrLocality.getDescriptor());
       try {
         @SuppressWarnings("unchecked")
         Class<? extends Message> routeLookupClusterSpecifierClass =