Instead of dynamically defaulting NodeRegistration.ImagePullPolicy,
which is common when doing defaulting depending on host state - e.g.
hostname, statically default it in v1beta3/defaults.go.
- Remove defaulting in checks.go
- Add one more unit test in checks_test.go
- Adapt v1beta2 conversion and fuzzer / round tripping tests
This also results in the default being visible when calling:
"kubeadm config print ...".
f01d251e38