Allow vcluster containers to run with arbitrary non-root UIDs on OpenShift

[simu]

This is required for the argocd-operator managed Redis. While the operator will auto-detect OCP4 when running on an OpenShift cluster, this logic doesn't work (and wouldn't help in any case) when running in a vcluster on OCP4.

Instead of doing some complicated configuration, we just allow the default serviceaccount in the vcluster namespace to use the nonroot-v2 SCC so that vcluster can sync pods with arbitrary non-root UIDs to the host cluster on OCP4.

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