Follow up on 5c94d4afcb
Changes:
* Revert s/KUBELET_KUBEADM_ARGS/KUBELET_ARGS
* Use /var/lib/kubernetes as the placeholder for other control planes env files
Follow up on https://gitlab.alpinelinux.org/alpine/aports/-/issues/11758
Introduced the following ENV variables read from the init:
KUBE_APISERVER_ARGS
KUBE_CONTROLLER_MANAGER_ARGS
KUBE_PROXY_ARGS
KUBE_SCHEDULER_ARGS
KUBELET_ARGS (renamed from KUBELET_KUBEADM_ARGS for name consistency)
