Modifies rescue test to work with servers built from Windows images

* Adds conditional logic that check's the image's metadata to see
  if it is a Windows image. If so, we skip the step of checking
  the number of disks while rescued as the default firewall rules
  are in place for the rescue host, which does not allow us to
  access the server remotely via WinRM

Change-Id: I683a4fdd499461ae7cf861bbe0ee53b7e04fe390
Merge "Modifies rescue test to work with servers built from Windows images"