src/service: flush dbus interface to not drop property updates
src/service: flush dbus interface to not drop property updates

This fixes a bug introduced by 7b27396055062ffbdb10a182d08465ed1f825f9d
where the call of `r_installer_set_operation()` was moved without moving
the associated call of `g_dbus_interface_skeleton_flush()`.

If not flushed, notifications for property updates will happen in and
idle loop. Thus multiple property updates might get aggregated.

If the same property is updated multiple times before a notification is
sent out, this will result in status update informations being lost.

A case where this could be observed quite often where the installation
status messages updates that randomly dropped some sub-steps from the
report.

Note that when introducing more fine-grained status updates (e.g.
reporting image write progress, progress updates may be performed
intentionally without calling the flush function in order to not DDoS
the d-bus interface.

Signed-off-by: Enrico Joerns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

jluebbe/rauc,ejoerns/rauc,rauc/rauc,rauc/rauc,jluebbe/rauc,jluebbe/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc