Add stop_grace_period for heat_engine container
Add stop_grace_period for heat_engine container

Heat engine requires longer shutdown time for cleanup. The default
10s is not enough. Let's increase it to something reasonable.

Change-Id: Ie80112d75a74b1a9d1d497edcfcda8dba3de5345
Closes-Bug: #1813771

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