Override ACL configs for savanna branches stable/*

Change-Id: I978b765e125c2d13362675a2e52e29b4d8bb4056
Reviewed-on: https://review.openstack.org/32327
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins