Write permissions on volume mount with security context fsgroup option

@protosam - So the problem is pod never starts as the start up script fails to create a directory (for service) under /opt/var/logs/docker/<service_name>.

Error: mkdir: cannot create directory '/opt/var/logs/docker/local-service/': Permission denied

So I already tested with another image whose start up script does not create a folder. And when I run a pod from the image, the volume gets mapped