Test failure: ros_network_default.test fails due to unexpected topic /gazebo/performance_metrics

[giusebar]

Description

The test ros_network_default.test in the gazebo_ros package is failing due to the extra topic /gazebo/performance_metrics available in the test output.
The stack trace of the failure is the following:

[gazebo_ros.rosunit-ros_network_by_default/test_extra_topics][FAILURE]----------
Items in the first set but not the second:
'/gazebo/performance_metrics'
  File "/usr/lib/python3.8/unittest/case.py", line 60, in testPartExecutor
    yield
  File "/usr/lib/python3.8/unittest/case.py", line 676, in run
    self._callTestMethod(testMethod)
  File "/usr/lib/python3.8/unittest/case.py", line 633, in _callTestMethod
    method()

The failure is related to this assertion:

Expected: set([])
Actual: {'/gazebo/performance_metrics'}

Proposed Solution

The /gazebo/performance_metrics topic should be added to the list of expected topics in the test gazebo_network_api.yaml expected topic.