[gardening] Mark co19 LibTest/io/Link/rename_A02_t01 flaky

Issue dart-lang/co19#174

TBR=kustermann@google.com

Change-Id: I69070d0bf6d27a7e5aed93c1fde36c1a3960178b
Reviewed-on: https://dart-review.googlesource.com/c/81273
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>

tests/co19_2/co19_2-kernel.status

@@ -1,6 +1,7 @@
 # Copyright (c) 2018, 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.
+LibTest/io/Link/rename_A02_t01: Pass, Fail # Issue https://github.com/dart-lang/co19/issues/174
 LibTest/io/RawDatagramSocket/any_A01_t02: Pass, Fail # Issue https://github.com/dart-lang/co19/issues/170
 LibTest/io/RawDatagramSocket/asBroadcastStream_A01_t02: Pass, Fail # Issue https://github.com/dart-lang/co19/issues/170
 LibTest/io/RawDatagramSocket/distinct_A01_t05: Pass, Fail # Issue https://github.com/dart-lang/co19/issues/170