Currently, the quota API/CLI allows users to set
quotas for current tenant only. However, admin
users needs the ability to set quota for other
tenants. For example:
$ source /opt/stack/devstack/openrc admin admin
$ openstack appcontainer quota update --containers 100 <DEMO_TENANT_UUID>
Closes-Bug: #1807620
Change-Id: I9109d968d8010692644fd004a8085a43e1bdf60f