manipulate network service in %post (#1369794)

Due to #1369794 , anaconda cannot currently manipulate sysv
services in F25+. So to work around this, take 'network' out of
the services lines in all kickstarts and instead manipulate
it in the %post section, with chkconfig.

Also remove rsyslog from the Atomic image services line because
it doesn't appear to be included in the OStree tree at present
and so attempting to enable the service breaks Atomic image
compose, see e.g.:

https://kojipkgs.fedoraproject.org//work/tasks/9022/15349022/oz-x86_64.log

also correct the name of the ssh service in fedora-arm-base.ks;
it's sshd not ssh.

fedora-cloud-atomic-pxetolive.ks

@@ -14,7 +14,7 @@ network --bootproto=dhcp --device=link --activate
 part / --fstype="ext4" --size=6000
 part /boot --size=500 --fstype="ext4"
 shutdown
-services --disabled=docker-storage-setup,network
+services --disabled=docker-storage-setup
 services --enabled=NetworkManager,sshd,cloud-init,cloud-init-local,cloud-config,cloud-final
  
 ostreesetup --nogpg --osname=fedora-atomic --remote=fedora-atomic --url=http://kojipkgs.fedoraproject.org/mash/atomic/22/ --ref=fedora-atomic/f22/x86_64/docker-host
@@ -28,4 +28,9 @@ userdel -r none
 # We copy content of separate /boot partition to root part when building live squashfs image,
 # and we don't want systemd to try to mount it when pxe booting
 cat /dev/null > /etc/fstab
+
+# Disable network service here, as doing it in the services line
+# fails due to RHBZ #1369794
+/sbin/chkconfig network off
+
 %end