Description of problem:
When editing VM or importing VMs from external provider, the operating system dropbox is not listing newer releases of Ubuntu from 14.10 and later.
The missing Ubuntu releases are from 14.10 to 17.10.

Ubuntu releases naming scheme (releases marked with * are already listed in OS dropbox):
Ubuntu 17.10 - Artful Aardvark
Ubuntu 17.04 - Zesty Zapus
Ubuntu 16.10 - Yakkety Yak
Ubuntu 16.04 - Xenial Xerus
Ubuntu 14.10 - Utopic Unicorn
Ubuntu 14.04 - Trusty Tahr *
Ubuntu 13.10 - Saucy Salamander *
Ubuntu 13.04 - Raring Ringtail *
Ubuntu 12.10 - Quantal Quetzal *
Ubuntu 12.04 - Precise Pangolin *

Version-Release number of selected component (if applicable):
ovirt-engine-4.2.0-0.0.master.20171103160151.gitcf446d9.el7.centos

How reproducible:
100%

Steps to Reproduce:
1. Browse Webadmin -> Compute -> virtual machines -> edit virtual machine, drop operating system dropbox.
2.
3.

Actual results:
Not all available Ubuntu releases (from 2014 and later) are listed in the dropbox.

Expected results:
Newer releases of Ubuntu should be listed also.

Additional info:
Screenshot attached.