Merge branch 'g.hickman-conditional-enforcement-pipeline-execution-jul-17' into 'master'

Share a sample yml for conditional enforcement in pipeline execution policies

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/159823



Merged-by: Russell Dickenson <rdickenson@gitlab.com>
Approved-by: Martin Čavoj <mcavoj@gitlab.com>
Approved-by: Russell Dickenson <rdickenson@gitlab.com>
Reviewed-by: Martin Čavoj <mcavoj@gitlab.com>
Reviewed-by: Ryan Lehmann <rlehmann@gitlab.com>
Co-authored-by: Alan (Maciej) Paruszewski <mparuszewski@gitlab.com>
Co-authored-by: Grant Hickman <ghickman@gitlab.com>