Fix compatibility with oslo.db 12.1.0
Fix compatibility with oslo.db 12.1.0

oslo.db 12.1.0 has changed the default value for the 'autocommit'
parameter of 'LegacyEngineFacade' from 'True' to 'False'. This is a
necessary step to ensure compatibility with SQLAlchemy 2.0. However, we
are currently relying on the autocommit behavior and need changes to
explicitly manage sessions. Until that happens, we need to override the
default.

Signed-off-by: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>
Change-Id: I57b8cce28c2ad7899b831067c94b9d913f3f1334

openstack/heat,openstack/heat