Remove disused `build_cache_images` task, and
update relevant dockerfiles for F30.
Fix problem of cloud-init failing to expand root-device on boot
(/var/lib/cloud/instance left in improper state).
Fix problem of cloud-init racing with google-network-daemon.service on
boot (looking for cloudconfig metadata too early). Causing
root-device to _sometimes_ fail to expand.
Fix problem of hack/get_ci_vm.sh argument passing.
Signed-off-by: Chris Evich <cevich@redhat.com>