Don't retry creating route if it already exists

pkg/cloudprovider/providers/gce/gce.go

@@ -2400,8 +2400,13 @@ func (gce *GCECloud) CreateRoute(clusterName string, nameHint string, route *clo
 		Description:     k8sNodeRouteTag,
 	}).Do()
 	if err != nil {
+		if isHTTPErrorCode(err, http.StatusConflict) {
+			glog.Info("Route %v already exists.")
+			return nil
+		} else {
 			return err
 		}
+	}
 	return gce.waitForGlobalOp(insertOp)
 }