rbd: restart thick-provisioned PVC snapshot restoring after aborting
rbd: restart thick-provisioned PVC snapshot restoring after aborting

In case restoring a snapshot of a thick-PVC failed during DeepCopy(),
the image will exist, but have partial contents. Only when the image has
the thick-provisioned metadata set, it has completed DeepCopy().

When the metadata is missing, the image is deleted, and an error is
returned to the caller. Kubernetes will automatically retry provisioning
on the ABORTED error, and the restoring will get restarted from the
beginning.

Signed-off-by: Niels de Vos <7bda0c0ee7f47171cc808e9e60292cbc5d8140dd@redhat.com>

ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi