WHAT
The 3scale operator needs to be opinionated about some env vars on 3scale deployments. However there are others that could be made configurable by the user. Right now, the operator will revert some env vars. There's inconsistency between the deployments managed by the operator. Some more context in chat here.

HOW
Investigate options/patterns for managing env vars on 3scale deployments which will allow for some env vars being configurable and others not. Define a pattern of usage and implement on at least one Deployment.

DONE
Ensure the pattern of usage for env vars is consistent and feasible for all deployments.
Document the new usage pattern for users.
If not implemented for all deployments create follow on JIRAs to cover.