* Fix kubectl explain bug when additionalProperties in schema defines as:
`additionalProperties: true` to ignore iterating.
* trigger error on kubectl explain with integration test on crd with non bool additionalfields
* add changes to fix the problem
* replace sleep with loop and retry for kubectl explain integration test
* replaced testdata file with inline create
Kubernetes-commit: 834658cb26c1cfbb2b41ac2f04711563ee534682