Openshift-controller-manager: openshift container platform: information disclosure via environment variable injection

A flaw was found in the OpenShift Container Platform build system. A user with the `edit` ClusterRole can inject arbitrary environment variables, such as `LD_PRELOAD` or `http_proxy`, into `docker-build` containers through the `buildconfigs/instantiate` API. This incomplete fix for a previous vulnerability allows for information disclosure, specifically impacting the confidentiality of build traffic.