tests, storage/restore: Refactor tests that use `Update`
tests, storage/restore: Refactor tests that use `Update`

Refactor the tests to simplify them and allow smoother conversion to use
`Patch` instead of `Update`.

Signed-off-by: Edward Haas <416ab6a6c3e37a8cab0d365516e79cce8f9be5ad@redhat.com>

kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt