Namespace license checks for preventing committing secrets

Related to https://gitlab.com/gitlab-org/gitlab-ee/issues/2335

Prevent committing secrets (EES / Bronze)

1. Nothing to do as this is already part of Push Rules and is previously covered once Push Rules has been put behind the license check.

2. How to handle for future cases where this has already been set?

Introduced in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/731 by @felipe_artur

Part of https://gitlab.com/gitlab-org/gitlab-ee/issues/2573

closed