Install gcloud on all images

For https://gitlab.com/gitlab-org/security/omnibus-gitlab/-/issues/3#note_1231931392

This adds gcloud to all builder images where awscli was also installed so that we can start sync'ing all packages to GCS buckets. This change reverts some of the changes made previously in !246 (merged) which allowed us to selectively choose the gcloud snippet for Ubuntu which is no longer necessary since we are now installing gcloud by default.