* Previously, configuration for the q-l3 agent was creating a
tenant-owned router. This change maintains that behaviour if
namespaces are enabled, but creates a public (not tenant-owned)
router if namespaces are disabled. Since the L3 agent can only
manage a single router if namespaces are disabled, the change
ensures that the single router can be shared by multiple tenants.
* Add tempest configuration for the public router.
Change-Id: I2878a7eb9797bfd71082a55d4773519dc5198abc
31c94ab510