Grenade jobs stop services, check fip connectivity
for a nova server and then upgrade to next release.
But since ovn data plane and db services are stopped along
with other services, fip connectivity fails as a result.
We shouldn't stop these services along with other
neutron services. This patch adds a new variable
"SKIP_STOP_OVN" which can be used by grenade jobs
to skip stop of ovn services.
This will also fix the ovn grenade jobs.
Also source fixup_stuff.sh so function fixup_ovn_centos
is available. It's already sourced in stack.sh but
that's not used in grenade run.
Change-Id: I94818a19f19973779cb2e11753d2881d54dfa3bc
yatinkarel
6f545e2567