If the resource handle has data from a structured parameter model, then we need
to pass that to the DRA driver kubelet plugin. Because Kubernetes uses
gogo/protobuf, we cannot use "optional" for that new optional field and have to
resort to "repeated" with a single repetition if present.
This is a new, backwards-compatible field.
That extending the resource.k8s.io changes the checksum of a kubelet checkpoint
is unfortunate. Updating the test cases is a stop-gap measure, the actual
solution will have to be something else before beta.