Currently, Kubernetes supports running as different user (RunAsUser),
but it only supports UIDs, which does not work on Windows.
Which is why the field SecurityContext.WindowsOptions.RunAsUserName
was introduced, to allow us to run the container entrypoints with
a different user than its default one.
This commit adds E2E tests which will validate this behaviour. The
tests are Windows only, and they will be skipped if --node-os-distro
is not "windows".