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

sdk/lib/_internal/pub_generated/test/lish/package_validation_has_a_warning_and_continues_test.dart

 // Copyright (c) 2013, 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:convert';
 
 import 'package:scheduled_test/scheduled_server.dart';
 import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:shelf/shelf.dart' as shelf;
@@ skipping 14 matching lines @@
 
     var server = new ScheduledServer();
     d.credentialsFile(server, 'access token').create();
     var pub = startPublish(server);
     pub.writeLine("y");
     handleUploadForm(server);
     handleUpload(server);
 
     server.handle('GET', '/create', (request) {
       return new shelf.Response.ok(JSON.encode({
-        'success': {'message': 'Package test_pkg 1.0.0 uploaded!'}
+        'success': {
+          'message': 'Package test_pkg 1.0.0 uploaded!'
+        }
       }));
     });
 
     pub.shouldExit(exit_codes.SUCCESS);
     pub.stdout.expect(consumeThrough('Package test_pkg 1.0.0 uploaded!'));
   });
 }