[rdo-list] package list for rdo oooq builds

FYI.. We've known for quite some time that maintaining a list of packages for image builds [2] is not ideal. We need to push this review along [1]. This relies on DIB for the package list vs.. us specifying the list in the variables. We're going to make this a priority now. Please review [1] Thanks! [1] https://review.gerrithub.io/#/c/280666 [2] https://github.com/redhat-openstack/ansible-role-tripleo-image-build/