* The init-container (pod.beta.kubernetes.io/init-containers) annotations used to accept capitalized field names that could be accidentally generated by the k8s.io/kubernetes/pkg/api package. Using an upper case field name will now return an error and all users should use the versioned API types from `pkg/api/v1` when serializing from Golang.

## Action Required Before Upgrading

* Important Security-related changes before upgrading