ostree installer: Add dbus-daemon to extra_runroot_packages
    
    The flatpak embedding process needs to run a local DBus session so that
    flatpak can talk to flatpak-oci-authenticator to authenticate (no-op)
    to registry.fedoraproject.org.
    
    https://pagure.io/fedora-lorax-templates/pull-request/47
    Signed-off-by: Owen W. Taylor <otaylor@fishsoup.net>