gluon-ebtables-limit-arp: stop for autoupdater (#3162)

Stop and start the gluon-arp-limiter service before the network is
brought down when commencing update.

Start the service after the network is brought back up when aborting.

Signed-off-by: David Bauer <mail@david-bauer.net>

package/gluon-ebtables-limit-arp/files/usr/lib/autoupdater/abort.d/15start-arp-limiter

+#!/bin/sh
+
+. /lib/gluon/autoupdater/lib.sh
+
+# Start after network
+start_enabled gluon-arp-limiter

package/gluon-ebtables-limit-arp/files/usr/lib/autoupdater/upgrade.d/05stop-arp-limiter

+#!/bin/sh
+
+. /lib/gluon/autoupdater/lib.sh
+
+# Stop before network
+stop gluon-arp-limiter