upower: Update for UPower upstream changes

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Manually calls D-Bus

Static introspection data was removed from systemd so use our tiny
subset manually here

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>