Clean up imports in analysis_server and analyzer_cli (and one missed in analyzer)

pkg/analysis_server/test/services/index/local_index_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.
 
 library test.services.src.index.local_index;
 
 import 'package:analysis_server/src/services/index/index_contributor.dart';
 import 'package:analysis_server/src/services/index/local_index.dart';
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
+import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../abstract_context.dart';
 import '../../utils.dart';
 import 'store/single_source_container.dart';
 
 main() {
   initializeTestEnvironment();
@@ skipping 86 matching lines @@
     Source source = addSource(path, content);
     CompilationUnit dartUnit = resolveLibraryUnit(source);
     index.index(context, dartUnit);
     return source;
   }
 
   void _indexTest(String content) {
     _indexLibraryUnit('/test.dart', content);
   }
 }