Set asset image name properly for all possible CE/EE project names
Set image name correctly for asset docker image when built in gitlab-ce, gitlabhq, gitlab-ee projects.
Right now, we are doing the conversion logic in omnibus-gitlab. With https://gitlab.com/charts/gitlab/issues/942 , we are moving CNG release to dev, so we will have to replicate it there too. I think it is better just to do this here. It will reduce the work in omnibus-gitlab, as well as CNG.
Related to https://gitlab.com/charts/gitlab/issues/1218