Revert "fedora: Use Atomic installtree/ISO for cloud image builds"
    
    We can't use the Atomic Host installer image because it runs at the
    same time the image builds do. See [1].
    
    [1] https://src.fedoraproject.org/rpms/pungi/pull-request/://docs.pagure.org/pungi/phases.html
    
    This reverts commit 97b45259db5059d45d9b34a347a32dd8cffc9ef0.
    
    Signed-off-by: Dusty Mabe <dusty@dustymabe.com>