Use "package:" imports for pub.

test/lish/preview_errors_if_private_test.dart

Index: test/lish/preview_errors_if_private_test.dart
diff --git a/test/lish/preview_errors_if_private_test.dart b/test/lish/preview_errors_if_private_test.dart
index 5884c1e561b84327f1f017558b3a4d3ebd9c8741..20296c8ba7314e6f0d6f3db85b0e2900b8161923 100644
--- a/test/lish/preview_errors_if_private_test.dart
+++ b/test/lish/preview_errors_if_private_test.dart
@@ -2,9 +2,9 @@
 // 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:pub/src/exit_codes.dart' as exit_codes;
 import 'package:scheduled_test/scheduled_test.dart';
 
-import '../../lib/src/exit_codes.dart' as exit_codes;
 import '../descriptor.dart' as d;
 import '../test_pub.dart';