Code coverage breaks if you specify a different compiler

[flynneva]

Description

It looks like the CMAKE args are not forwarded to the coverage commands:

Expected Behavior

Code coverage mixin still works if specifying a different compiler via --cmake-args

Actual Behavior

Code coverage mixin fails, since I think it uses a different compiler (whatever the system default is) to generate code coverage.

See this job for an example.

To Reproduce

1. See this commit where I disabled the code-coverage mixin from this action on how to reproduce

System (please complete the following information)

• OS: Any
• ROS 2 Distro: Any

[flynneva]

fyi @christophebedard

[christophebedard]

It might work if you provide the CMake args through the colcon-defaults input instead.