topic statistic tests failing with Connext

[dirk-thomas]

In the nightly jobs using only Connext these test fail since they have been added in #1080:

• http://build.ros2.org/view/Rci/job/Rci__nightly-connext_ubuntu_focal_amd64/43/testReport/rclcpp/TestSubscriptionTopicStatisticsFixture/test_receive_stats_for_message_no_header/
• http://build.ros2.org/view/Rci/job/Rci__nightly-connext_ubuntu_focal_amd64/43/testReport/rclcpp/TestSubscriptionTopicStatisticsFixture/test_receive_stats_for_message_with_header/

@prajakta-gokhale @dabonnie Will either of you be able to work on this this in the near term?

[dabonnie]

I can take a look (next week), but it looks like you beat us to it :-)

[dirk-thomas]

I can take a look (next week)

It would still be good to take another look at the test. While my PR makes it pass with Connext I am not sure why the original test assumed every metrics message has non-zero samples.

but it looks like you beat us to

Please consider reviewing the pending pull request if you have a chance.

[dabonnie]

@dirk-thomas will review by EOD.