Description:

The CI_COMMON_ENV_POD feature flag reduces pod.yaml size by storing Harness internal environment variables in a shared ConfigMap. However, custom stage variables are still duplicated across every step container, even when not referenced by that step.

Request:

Extend this optimization to include custom stage variables in the common ConfigMap, and only inject variables into steps that actually use them.

This would significantly reduce pod.yaml size for pipelines with many steps and stage variables, helping prevent "etcdserver: request is too large" failures in Kubernetes environments.