Enable fedora-readonly.service and fedora-import-state.service
    
    fedora-readonly.service is a oneshot service that runs during bootup
    and configures read-only root. It used to be permanently enabled using
    a symlink in /usr/lib/systemd/system, and moving it to presets is a
    step to allowing it to be disabled.
    
    fedora-import-state.service is a oneshot service that runs after the
    switch to the real filesystem and and moves some state from /run to
    /etc. It shouldn't be used anymore, and programs should instead check
    /run for their configuration. networking and some fcoe-related stuff
    used in dracut still uses that, so until that is fixed in those
    projects, we need this enabled.
    
    Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>