Downstream Component Images (PROJQUAY-828)

[alecmerdler]

Issue: https://issues.redhat.com/browse/PROJQUAY-828

Changelog: Add initial downstream release Kustomize overlay for managed component container images.

Docs: Ensure that users know how to create redhat-pull-secret (documentation exists).

Testing:

1. Create redhat-pull-secret in same namespace as QuayRegistry.
2. Add the above pull secret name to list of imagePullSecrets for the ServiceAccount named default in your namespace so it can pull the private images.
3. Create zero-config QuayRegistry.

Expected:

• All containers pull successfully.

Details: Adds Kustomize overlays for an initial downstream release using official Red Hat container images for relevant managed components. These container images require a Red Hat pull secret.

Also switches to deploy CentOS-based Postgres image when running in upstream mode.

Remaining Issues:

• Ensure pg_trgm extension created for quay database
• Clair database doesn't have clair DB being created
• Switch to using CentOS Postgres image for upstream and confirm all env vars and scripts continue working