Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/index/index_test.dart

Index: pkg/analysis_server/test/services/index/index_test.dart
diff --git a/pkg/analysis_server/test/services/index/index_test.dart b/pkg/analysis_server/test/services/index/index_test.dart
index 5a1f093f61d9c8b000c367adbe71909ffcee2388..61b43754711da9994f405a785bc84ad91f00f812 100644
--- a/pkg/analysis_server/test/services/index/index_test.dart
+++ b/pkg/analysis_server/test/services/index/index_test.dart
@@ -7,16 +7,18 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/summary/idl.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:typed_mock/typed_mock.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../abstract_single_unit.dart';
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(IndexTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(IndexTest);
+  });
 }
 
 @reflectiveTest