xds: enable RLS in xDS by default (#6343)

Author: dfawley

internal/envconfig/xds.go

@@ -81,10 +81,10 @@ var (
 	XDSFederation = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FEDERATION", true)
 
 	// XDSRLS indicates whether processing of Cluster Specifier plugins and
-	// support for the RLS CLuster Specifier is enabled, which can be enabled by
+	// support for the RLS CLuster Specifier is enabled, which can be disabled by
 	// setting the environment variable "GRPC_EXPERIMENTAL_XDS_RLS_LB" to
-	// "true".
-	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", false)
+	// "false".
+	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", true)
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
 	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")

xds/internal/xdsclient/xdsresource/unmarshal_rds_test.go

@@ -1299,7 +1299,7 @@ func (s) TestRoutesProtoToSlice(t *testing.T) {
 							ClusterSpecifier: &v3routepb.RouteAction_ClusterSpecifierPlugin{}}},
 				},
 			},
-			wantRoutes: []*Route{},
+			wantErr: true,
 		},
 		{
 			name: "default totalWeight is 100 in weighted clusters action",