The answer is yes. How depends on if the disk is a raw file or a zvol. A zvol can be expanded from the UI. A raw file would require a tiny (one line) of CLI work.
@Tim1962 You now need to expand the filesystem within your Ubuntu VM. The steps will depend on whether you installed it using LVM or not. One way to do this is to boot the VM from an Ubuntu LiveCD and use gparted. It can also be done using CLI tools, there are plenty of examples on the web, here are just two refs: