let objects without metadata pass through the managedFields admission controller
let objects without metadata pass through the managedFields admission controller

Not all objects provide metadata. There might be extention servers that allow for creating objects without the metadata field.

This PR changes the managedFileds admission to deal with objects without the metadata field.
Object without that field will be passed directly to the wrapped admission controller for further validation.

Kubernetes-commit: 3dbaf305ae1e52105a338987f3770ff104def68b

kubernetes/apiserver,kubernetes/apiserver