Retry cinder volume state

Retry cinder volume state

The service of cinder-volume restarts too quickly after package
installation with default/incorrect configuration and goes over restart
threshold, so systemd stops attempt to restart any further causing
state faulure. To fix it properly the RestartSec (i.e. restart delay)
param should be added into cinder-volume.service unit.

Change-Id: Ic8591e8ef52a3d439122f276d275e56bd2442ce6
Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>
(cherry picked from commit 1ea49591080442d8db86fff60031d3dc41142274)