Test for detecting overriding of CI server values
What does this MR do?
Adds a list of predefined CI server env vars and runs a test to ensure we don't accidentally re-use/overwrite an existing variable whilst developing new features.
Why was this MR needed?
What's the best way to test this MR?
Run TestPredefinedServerVariables.
What are the relevant issue numbers?
Edited by Steve Xuereb