systemvm: Ensure cloud service reboots after failure (#2916)

This fixes an issue for systemvms (CPVM and SSVM) on VMware, as eth0
is not programmed (link-local) the networking.service fails to start
which is a dependency for cloud-postinit service. When cloud-postinit
service fails to start/run, it fails to start the agent (cloud) process.
This fixes the smoketest failures we saw in case of VMware 6.5 with
4.11.

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: yadvr

systemvm/debian/etc/systemd/system/cloud-postinit.service

@@ -2,7 +2,6 @@
 Description=CloudStack post-patching init script
 After=cloud-early-config.service network.target local-fs.target
 Before=ssh.service
-Requires=networking.service
 
 [Install]
 WantedBy=multi-user.target

systemvm/debian/etc/systemd/system/cloud.service

@@ -9,5 +9,4 @@ WantedBy=multi-user.target
 Type=simple
 WorkingDirectory=/usr/local/cloud/systemvm
 ExecStart=/usr/local/cloud/systemvm/_run.sh
-Restart=always
-RestartSec=5
+Restart=on-failure