ofono: Disable ril and rildev plugins when running ofonod manually

This matches the command used in ofono.service (minus the --nodetach,
because we want the process to detach so we can do other things in the
test). This eliminates some spurious AppArmor failures caused by the RIL
code, and allows ofono to work (the RIL plugin does not work on the
i.MX6).

Bug-Apertis: https://bugs.apertis.org/show_bug.cgi?id=681



Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Philip Withnall <philip.withnall@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D2278