:farmer: `test_cli_remapping` flaky test

Bug report

Required Info:

• Operating System:
  • Windows (and sometimes Ubuntu 20.04)
• Installation type:
  • Source
• Version or commit hash:
  • Rolling / Foxy

Steps to reproduce issue

• Run a build in nightly windows or nightly repeated jobs
• See test_cli_remapping fail if you're lucky

Expected behavior

• test_cli_remapping should pass

Actual behavior

• test_cli_remapping is failing sometimes

Additional information

Log output:
Although most of the tests have different names, the log output is very similar in all of them:

Traceback (most recent call last):
  File "C:\ci\ws\src\ros2\system_tests\test_cli_remapping\test\test_cli_remapping.py", line 149, in test_topic_and_service_replacement
    self.assertIn(topic_and_service_replacement, self.get_topics())
AssertionError: '/remapped/ts5907_00_20_08' not found in ['/fully/qualified/name', '/ns/s5749_00_20_08/original_node_name/private/name', '/ns/s5749_00_20_08/relative/name', '/original/namespace/node_6563_00_20_08/private/name', '/original/namespace/original_node_name/private/name', '/original/namespace/relative/name', '/parameter_events', '/remapped/t1668_00_20_08', '/rosout']

Reference builds:

• Nightly Windows Repeated: https://ci.ros2.org/view/nightly/job/nightly_win_rep/2871/
• Foxy Nightly Connext: https://build.ros2.org/view/Fci/job/Fci__nightly-connext_ubuntu_focal_amd64/480/

Buildfarmer stats

Flakiness ratio in the last 30 days:

• Job: Fci__nightly-connext_ubuntu_focal_amd64
  • Last 30 builds: 3 builds failed, 10% with error
  • Last 7 builds: 1 builds failed, 14.28% with error
• Job: nightly_win_rel
  • Last 30 builds: 5 builds failed, 16.66% with error
  • Last 7 builds: 1 builds failed, 14.28% with error
• Job: nightly_win_rep
  • Last 30 builds: 10 builds failed, 33.33% with error
  • Last 7 builds: 3 builds failed, 42.85% with error

This test has failed on the following jobs:

They're mostly Repeated and windows jobs

Start with system_tests/test_cli_remapping/test/test_cli_remapping.py, especially the failure at line 149, and reproduce the test in the referenced repeated Windows or Ubuntu jobs. Compare the logged topic and service names across failures; done means test_cli_remapping passes reliably in the affected nightly jobs.