Update the analysis server integration tests to always run on the analysis driver.

pkg/analysis_server/test/integration/analysis/update_content_driver_test.dart

-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'package:test_reflective_loader/test_reflective_loader.dart';
-
-import 'update_content_test.dart';
-
-main() {
-  defineReflectiveSuite(() {
-    defineReflectiveTests(UpdateContentTest_Driver);
-  });
-}
-
-@reflectiveTest
-class UpdateContentTest_Driver extends AbstractUpdateContentTest {
-  @override
-  bool get enableNewAnalysisDriver => true;
-}