Support a custom CA for the certificate of the integrated OpenShift Container Platform registry

1. Proposed title of this feature request

Support a custom CA for the certificate of the integrated OpenShift Container Platform registry.

2. What is the nature and description of the request?

Third-party storage providers offer S3 buckets which can be used for the integrated OpenShift Container Platform registry. In case an S3 storage backend is signed with an external CA, it would be needed to trust in it.

The request is to be able to configure the Registry Operator in order to trust in the external CA.

3. Why does the customer need this? (List the business requirements here)

The customer needs to use an S3 bucket for their integrated OpenShift Container Platform registry whose provider uses a different CA.

4. List any affected packages or components.

Integrated OpenShift Container Platform registry