Update the CRD yaml manifest mentioned in custom_object example

[Priyankasaggu11929]

Link to the issue (please include a link to the specific documentation or example):

https://github.com/kubernetes-client/python/blob/master/examples/custom_object.py#L22-L38

Description of the issue (please include outputs or screenshots if possible):

The custom_object.py uses a Custom Resource Definition (CRD) to create a custom object. And so, it mentions to apply the following yaml manifest first (before executing the example script):

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: crontabs.stable.example.com
spec:
  group: stable.example.com
  versions:
    - name: v1
      served: true
      storage: true
  scope: Namespaced
  names:
    plural: crontabs
    singular: crontab
    kind: CronTab
    shortNames:
    - ct

But on applying the above yaml manifest, it throws the following error:

The CustomResourceDefinition "crontabs.stable.example.com" is invalid: spec.versions[0].schema.openAPIV3Schema: Required value: schemas are required

[Priyankasaggu11929]

/assign