Use systemctl to restart services
Use systemctl to restart services

The restart code for the live migration configure on the fly tests was
really really fragile clippings of old bits of devstack code that
barely worked (and assumed a very specific run environment).

Given that we're going to get rid of everything other than systemd in
devstack, just jump straight to using systemd primitives here. This
dramatically simplifies the code, and will ensure things actually
restart correctly.

Closes-Bug: #1687511

Change-Id: I914430d68f64d29932c9409d055b15e4cb384ec4

gooddata/openstack-nova,Juniper/nova,openstack/nova,Juniper/nova,gooddata/openstack-nova,rahulunair/nova,mahak/nova,vmturbo/nova,vmturbo/nova,phenoxim/nova,rajalokan/nova,klmitch/nova,vmturbo/nova,rahulunair/nova,Juniper/nova,rajalokan/nova,rajalokan/nova,mikalstill/nova,openstack/nova,Juniper/nova,phenoxim/nova,jianghuaw/nova,mahak/nova,jianghuaw/nova,gooddata/openstack-nova,mahak/nova,rahulunair/nova,klmitch/nova,rajalokan/nova,gooddata/openstack-nova,jianghuaw/nova,vmturbo/nova,openstack/nova,klmitch/nova,jianghuaw/nova,mikalstill/nova,klmitch/nova,mikalstill/nova