Disable sysbox inner image preloading for K8s deployments.

The feature is only useful when using "docker build" or "docker commit" to
create container images that come preloaded with inner container images. By
disabling it in K8s, sysbox pod stopping will become faster (and can be
significantly faster if the pod had a docker engine inside that pulled
lots of inner container images.

Signed-off-by: Cesar Talledo <cesar.talledo@docker.com>

k8s/systemd/sysbox-mgr.service

@@ -5,7 +5,7 @@ PartOf=sysbox.service
 [Service]
 Type=simple
 Type=notify
-ExecStart=/usr/bin/sysbox-mgr
+ExecStart=/usr/bin/sysbox-mgr --disable-inner-image-preload
 TimeoutStartSec=45
 TimeoutStopSec=90
 StartLimitInterval=0