Switch the default from non-driver to driver in several tests

pkg/analysis_server/test/services/correction/assist_test.dart

 // Copyright (c) 2014, 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 'dart:async';
 
 import 'package:analysis_server/plugin/edit/assist/assist_core.dart';
 import 'package:analysis_server/plugin/edit/assist/assist_dart.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/plugin/server_plugin.dart';
@@ skipping 27 matching lines @@
 class AssistProcessorTest extends AbstractSingleUnitTest {
   int offset;
   int length;
 
   ServerPlugin plugin;
   Assist assist;
   SourceChange change;
   String resultCode;
   LinkedEditGroup linkedPositionGroup;
 
-  @override
-  bool get enableNewAnalysisDriver => true;
-
   /**
    * Asserts that there is an [Assist] of the given [kind] at [offset] which
    * produces the [expected] code when applied to [testCode].
    */
   assertHasAssist(AssistKind kind, String expected) async {
     assist = await _assertHasAssist(kind);
     change = assist.change;
     // apply to "file"
     List<SourceFileEdit> fileEdits = change.edits;
     expect(fileEdits, hasLength(1));
@@ skipping 4674 matching lines @@
 
   @override
   final AstProvider astProvider;
 
   @override
   final CompilationUnit unit;
 
   _DartAssistContextForValues(this.source, this.selectionOffset,
       this.selectionLength, this.analysisContext, this.astProvider, this.unit);
 }