Infrom user why rt policy could not be set, infrom if is set. (backport #1705)

[mergify]

Print out information why setting of rt policy could not be set. Additionally inform if successfully set the rt policy

---

This is an automatic backport of pull request #1705 done by Mergify.

[mergify]

Cherry-pick of dd352eb has failed:

On branch mergify/bp/iron/pr-1705
Your branch is up to date with 'origin/iron'.

You are currently cherry-picking commit dd352eb.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   controller_manager/src/ros2_control_node.cpp

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[christophfroehlich]

Failed because of missing backport of #1142

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 62.16%. Comparing base (c2760b4) to head (f095128).
Report is 1 commits behind head on iron.

Files	Patch %	Lines
controller_manager/src/ros2_control_node.cpp	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             iron    #1709      +/-   ##
==========================================
- Coverage   62.17%   62.16%   -0.02%     
==========================================
  Files         109      109              
  Lines       12205    12205              
  Branches     8551     8548       -3     
==========================================
- Hits         7589     7587       -2     
  Misses        867      867              
- Partials     3749     3751       +2     

Flag	Coverage Δ
unittests	62.16% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
controller_manager/src/ros2_control_node.cpp	80.00% <0.00%> (ø)

... and 2 files with indirect coverage changes