controlplane init mutex configmap not properly reparented after backup/restore

What steps did you take and what happened: (a) velero-backup a namespace w/ CAPI-managed clusters/resources (b) delete the namespace (c) velero-restore the namespace w/ the CAPI-managed clusters/resources (d) observe that the configmap mutex is not properly adopted by the newly restored Cluster object

What did you expect to happen: proper adoption of the configmap by the Cluster so that subsequent "uninstallation" of the Cluster results in proper GC of the mutex configmap

Anything else you would like to add: a bunch of other adoption issues were fixed recently, looks like this was an oversight

see pkg bootstrap/kubeadm/internal/locking, the setMetadata func sets initial ownership, but thereafter ownership lingers unchanged, indefinitely

Environment:

• Cluster-api version: 1.2.7
• minikube/kind version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

/kind bug [One or more /area label. See https://github.com/kubernetes-sigs/cluster-api/labels?q=area for the list of labels]