Standardize gen 1 VM ISO attachment to SCSI controllers

[jocardeMSFT]

Issue

• https://dev.azure.com/msazure/One/_workitems/edit/27453506
• Gen 1 VMs were blocked from performing day 2 guest management enablement.
  • day 2 in this context means that the VM was originally provisioned without guest management enabled and guest management was enabled at a later time.
• The root cause of this issue was that the ISO containing the guest management binaries and scripts was attempting to be added to gen 1 VMs via the IDE controller (as compared to the SCSI controller for gen 2 VMs). ISOs cannot be attached to a VMs IDE controller while the VM is running. We do not shut down the VM for this process so the ISO addition was completely blocked.
   

Solution

• Standardize the ISO attachment process across gen 1 VMs and gen 2 VMs so the ISO can be attached to the SCSI controller for all VMs while the VM is running.

Validation Performed

• day 0 and day 2 guest management enablement on windows gen 1 and gen 2 VMs
• TODO: day 0 and day 2 guest management enablement on linux gen 1 and gen 2 VMs
• TODO: ArcVME2E and ssvm testing

[jocardeMSFT]

/azp run