[OCM] on-cluster console should disable update buttons in managed clusters

Managed OpenShift (OSD, ROSA) on-cluster console should have their update buttons greyed-out (disabled) so that customers don't suffer the error related to webhooks blocking updates. (since OSD and ROSA need the OCM UI or ROSA CLI in order to do updates)

As managed services governs when we allow specific update versions, this change would support that without letting the user encounter an unnecessary error.