epiphany/eos-updater/rpm-ostree: Support D-Bus call flags for interactivity

This ensures that the service we’re communicating with can’t pop up an unexpected polkit dialogue or other bit of UI if the gnome-software operation is non-interactive.

For each plugin, there are two commits: one which just changes the generated proxy API by adding the --glib-min-required argument to gdbus-codegen. Default values are used for all the calls, so there is no behavioural change.

The second commit changes the flags which are used (so introduces behavioural changes). Splitting the commits up should make things easier to review, since the first commit is entirely mechanical.

Signed-off-by: Philip Withnall pwithnall@endlessos.org