Generate constants in server as we do in plugin

pkg/analysis_server/test/analysis/notification_overrides_test.dart

Index: pkg/analysis_server/test/analysis/notification_overrides_test.dart
diff --git a/pkg/analysis_server/test/analysis/notification_overrides_test.dart b/pkg/analysis_server/test/analysis/notification_overrides_test.dart
index a64cc1b1b56bb8e34898619a7d6937f370dc7b4e..ab9efad025ec23f6c41b9b8b0c72bdde6387cee6 100644
--- a/pkg/analysis_server/test/analysis/notification_overrides_test.dart
+++ b/pkg/analysis_server/test/analysis/notification_overrides_test.dart
@@ -5,8 +5,8 @@
 import 'dart:async';
 
 import 'package:analysis_server/protocol/protocol.dart';
+import 'package:analysis_server/protocol/protocol_constants.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
-import 'package:analysis_server/src/constants.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -123,7 +123,7 @@ class AnalysisNotificationOverridesTest extends AbstractAnalysisTest {
   }
 
   void processNotification(Notification notification) {
-    if (notification.event == ANALYSIS_OVERRIDES) {
+    if (notification.event == ANALYSIS_NOTIFICATION_OVERRIDES) {
       var params = new AnalysisOverridesParams.fromNotification(notification);
       if (params.file == testFile) {
         overridesList = params.overrides;