webadmin : Optimise for virt store on volumes

This patch adds a check for eligibility to optimise
for virt store and just in case the options are not
enabled already, it adds the suggested options.

Change-Id: I6f995dec2258a3f5fc9673d5d075866b89f7773c
Signed-off-by: Anmol Babu <anbabu@redhat.com>