Ugprade oVirt's OpenShift instance to OKD 4.x

Reasons to do this:

• Automated OKD upgrades

• Support for OpenShift pipelines (Knative/Tekton)

Issues we need to solve:

• The OS for the OKD nodes (CentOS CoreOS 8.x not release yet)

• OKD Installer support for oVirt ('s patches not merged & released yet)