OADP / Virtualization supported backup types

Description of problem:

After a discussion with alitke@redhat.com we have concluded that b/r support will be limited to:

• CSI backups
• CSI backups with DataMover

This statement EXCLUDES:

• file system backup and restores as doc'd in [1]
• volumeSnapshot Backups and Restores,  using the snapshotLocation DPA configuration

[1] https://72372--ocpdocs-pr.netlify.app/openshift-enterprise/latest/backup_and_restore/application_backup_and_restore/backing_up_and_restoring/oadp-backing-up-applications-restic-doc

We will want to make that very clear to the customer in the current kubevirt section of the docs e.g. https://github.com/openshift/openshift-docs/pull/72372/files

Please let me know if there are any questions or concerns.