Fix journal log flood in headless mode

[kajusnau]

Description of changes

1. Follow Up Fix To Reduce Log Flooding In Headless Mode:

• Log flooding was previously fixed in Reduce journal log flood in headless mode #1021 but broke again after Desktop: Fix desktop services not starting after wlr-randr v0.5.0 #1022.
• This PR fixes log flooding in headless mode caused by these services: ewwbar, audio-control, and ghaf-launcher.
• Previous log flooding fix relied on wlr-randr exiting with an error code when no displays are connected.
  That no longer happens with wlr-randr 0.5.0, or at least doesn't happen as consistently.
  The fix in this PR now checks wlr-randr status and makes sure the number of displays connected is >0.

Checklist for things done

• Summary of the proposed changes in the PR description
• More detailed description in the commit message(s)
• Commits are squashed into relevant entities - avoid a lot of minimal dev time commits in the PR
• Contribution guidelines followed
• Ghaf documentation updated with the commit - https://tiiuae.github.io/ghaf/
• PR linked to architecture documentation and requirement(s) (ticket id)
• Test procedure described (or includes tests). Select one or more:
  • Tested on Lenovo X1 x86_64
  • Tested on Jetson Orin NX or AGX aarch64
  • Tested on Polarfire riscv64
• Author has run make-checks and it passes
• All automatic Github Action checks pass - see actions
• Author has added reviewers and removed PR draft status
• Change requires full re-installation
• Change can be updated with nixos-rebuild ... switch

Instructions for Testing

• List all targets that this applies to:
• Is this a new feature
  • List the test steps to verify:
• If it is an improvement how does it impact existing functionality?

[milva-unikie]

Lenovo-X1:

• The Lenovo X1 failed to log out via the GUI in the pre-merge pipeline.
• I reran the test locally, and it passed -> most likely there was a random glitch.
• Did a quick sanity check with X1, everything seems to be in order.

Orins:

• Based on pre-merge pipeline results, the log flooding on Orins has been fixed.
• It would probably be a good idea to also boot Orins with a display and check that they work properly.

[johannarautanen]

Tried the Orin AGX native from USB memory stick:
-while testing opening the application launching, the external display suddenly went back and the serial connection wasn't responding either.
black_screenissue.txt