move pkg/kubelet/apis/well_known_labels.go to staging/src/k8s.io/api/core/v1/
move pkg/kubelet/apis/well_known_labels.go to staging/src/k8s.io/api/core/v1/

Co-Authored-By: Weibin Lin <linweibin1@huawei.com>

Change-Id: I163b2f2833e6b8767f72e2c815dcacd0f4e504ea

Kubernetes-commit: b97557338520992dda0970058d4309da05208296

kubernetes/api