ffu: Add missing nova-manage db sync for Pike upgrade
ffu: Add missing nova-manage db sync for Pike upgrade

This would result in the failure of the online_data_migrations command
during the Ocata to Pike upgrade. The following Pike to Queens upgrade
would hide this failure by running both the sync and migrations again.

Change-Id: I51f40254acee435ed4e60c0e97b5ced86fd67fc2
Closes-bug: #1775868

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates