CLOUDSTACK-4246 VM deployment fails with global configuration parameter "vmware.nested.virtualization" enabled.

Signed-off-by: Sateesh Chodapuneedi <sateesh@apache.org>
CLOUDSTACK-4244. Unable to attach a volume to a VM deployed in Stopped (startvm=false) state.
While attaching a volume to a VM, create volume on the hypervisor only if the VM has been started on the it.