We should eliminate or explicitly define the dependencies between different ContainerOpts.

E.g.:

1. WithSnapshotter must be called before WithNewSnapshot to make it work.
2. WithSnapshotter or WithNewSnapshot must be called before WithUserID or WithUsername to make sure snapshotter is properly initialized.

In cri-containerd, we are using default snapshotter for now. And I just hit an issue that, I put WithNewSnapshot after WithUserID, and could not start that container if a User ID is specified for that container.

Not urgent, but just track the issue here.