Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/global/activate/unexpected_arguments_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 'package:scheduled_test/scheduled_test.dart';
 
 import '../../../lib/src/exit_codes.dart' as exit_codes;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
   integration('fails if there are extra arguments', () {
-    schedulePub(args: ["global", "activate", "foo", "1.0.0", "bar", "baz"],
+    schedulePub(
+        args: ["global", "activate", "foo", "1.0.0", "bar", "baz"],
         error: contains('Unexpected arguments "bar" and "baz".'),
         exitCode: exit_codes.USAGE);
   });
 }