Explicitly enable access to host DNS from pod/service IPs. Also fix the Kubernetes health checks to assert number of ready pods to match expectation, otherwise the check might skip a pod (e.g. `kube-proxy` one) which is not ready, allowing the test to proceed too early. Update DNS test to print more logs on error. Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>