Add no-shuffle tag (#88989)

packages/flutter/test/services/platform_channel_test.dart

@@ -2,6 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(gspencergoog): Remove this tag once this test's state leaks/test
+// dependencies have been fixed.
+// https://github.com/flutter/flutter/issues/85160
+// Fails with "flutter test --test-randomize-ordering-seed=20210826"
+@Tags(<String>['no-shuffle'])
+
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';