Add support to create Ubuntu images that are compatible with OS::Heat::SoftwareDeployment

[Giuseppe Petralia]

In order to use OS::Heat::SoftwareDeployment, a VM needs to include some tools as documented in here:

- https://ask.openstack.org/en/question/102594/osheatsoftwaredeployment-and-xenial-1604-custom-image/
- https://voipmagazine.wordpress.com/2015/06/13/building-linux-images-for-use-with-openstack-heat/
- https://docs.openstack.org/heat/latest/template_guide/software_deployment.html#custom-image-script

Also if I follow the custome-image-script procedure from OpenStack documentation for ubuntu bionic this fails hitting LP#1863122

As an operator I would like to have an action to retrofit into glance images that are compatible with Heat functionalities or adjust the Deployment guide to have a working procedure to build ubuntu images.