Images don't work without these fixes:
* Enable Network Manager.
* Disable cloud-init.
* Add Hyper-V modules into initramfs.
Fixes specific for RHEL:
* Create ifcfg-eth0 required by waagent.
* Install python3 and net-tools required by waagent.
Recommended changes:
* Use recommended kernel boot args.
* Disable kdump.
Since these images can be used to create multiple machines, they should
not have a unique machine-id attached to them. Replace /etc/machine-id
with an empty file so that it will be regenerated at boot time.
