Fix services usage when service name is using variable

What does this MR do?

Fixes usage of services when a name of service contains a variable. This is a fix for regression introduced with !596 (merged).

Why was this MR needed?

Please read #2636 (closed) for a reference

Are there points in the code the reviewer needs to double check?

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?

Closes #2636 (closed)

@ayufan Can you look on this?

@nick.thomas Could you take look on this?

assigned to @nick.thomas

@tmaczukin LGTM!

approved this merge request

marked the checklist item All builds are passing as completed

marked the checklist item Branch has no merge conflicts with master (if you do - rebase it please) as completed

merged