Topic remap test is failing regularly

[Karsten1987]

The topic remapping test is failing regularly on CI due to timeouts, e.g.:

02:07:44 22: Running main() from gmock_main.cc
02:07:44 22: [==========] Running 1 test from 1 test case.
02:07:44 22: [----------] Global test environment set-up.
02:07:44 22: [----------] 1 test from RosBag2PlayTestFixture
02:07:44 22: [ RUN      ] RosBag2PlayTestFixture.recorded_message_is_played_on_remapped_topic
02:08:44 1/1 Test #22: test_play_topic_remap__rmw_fastrtps_cpp ...***Timeout  60.10 sec
02:08:44 
02:08:44 0% tests passed, 1 tests failed out of 1
02:08:44 
02:08:44 Label Time Summary:
02:08:44 gmock    =  60.10 sec*proc (1 test)
02:08:44 
02:08:44 Total Test time (real) =  60.11 sec
02:08:44 
02:08:44 The following tests FAILED:
02:08:44 	 22 - test_play_topic_remap__rmw_fastrtps_cpp (Timeout)
02:08:44 Errors while running CTest
02:08:44 

https://ci.ros2.org/view/nightly/job/nightly_osx_extra_rmw_release/831/consoleFull#console-section-43

The problem is as usual a indeterministic execution of ROS2, which doesn't allow to verify an exact number of messages being transported.