[PWGUD] flowCorrelationsUpc: use truegapside producer instead of calculating it in the test

[miedema-11]

No description provided.

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 0 warnings, 🔕 0 disabled

[vkucera]

Please make it clear in your PR title which part of the framework has changed.

[vkucera]

Still no mention of the location of the changes in the repo.

[miedema-11]

Still no mention of the location of the changes in the repo.

I don't understand what do you mean by the location of the repo. The changes of the producer is not contributed by this task. I think my code is completely able to merge

[miedema-11]

This PR is ready to be merged, thank you

[vkucera]

Still no mention of the location of the changes in the repo.

I don't understand what do you mean by the location of the repo. The changes of the producer is not contributed by this task. I think my code is completely able to merge

By location, I mean name of the file or task or framework feature. You are supposed to summarise what you changed and where. Otherwise the title is too vague. See the guidelines.