Remove _get_router & _create_router methods

As tempest.scenario.manager was announced stable interface in Tempest 27.0.0[1] it can be now reused in plugins.

Replaced methods:
	* _get_router
	* _create_router

Etherpad concerning this effort:
https://etherpad.opendev.org/p/tempest-scenario-manager-cleanup

[1] https://docs.openstack.org/releasenotes/tempest/v27.0.0.html#release-notes-27-0-0

Change-Id: I70e168160c1bfb8e5025bef8105d59a7dcc9da07
diff --git a/manila_tempest_tests/tests/scenario/manager.py b/manila_tempest_tests/tests/scenario/manager.py
index 85d2f27..4df0023 100644
--- a/manila_tempest_tests/tests/scenario/manager.py
+++ b/manila_tempest_tests/tests/scenario/manager.py
@@ -433,50 +433,6 @@
 
         return rules
 
-    def _get_router(self, client=None, tenant_id=None):
-        """Retrieve a router for the given tenant id.
-
-        If a public router has been configured, it will be returned.
-
-        If a public router has not been configured, but a public
-        network has, a tenant router will be created and returned that
-        routes traffic to the public network.
-        """
-        if not client:
-            client = self.routers_client
-        if not tenant_id:
-            tenant_id = client.tenant_id
-        router_id = CONF.network.public_router_id
-        network_id = CONF.network.public_network_id
-        if router_id:
-            body = client.show_router(router_id)
-            return body['router']
-        elif network_id:
-            router = self._create_router(client, tenant_id)
-            kwargs = {'external_gateway_info': dict(network_id=network_id)}
-            router = client.update_router(router['id'], **kwargs)['router']
-            return router
-        else:
-            raise Exception("Neither of 'public_router_id' or "
-                            "'public_network_id' has been defined.")
-
-    def _create_router(self, client=None, tenant_id=None,
-                       namestart='router-smoke'):
-        if not client:
-            client = self.routers_client
-        if not tenant_id:
-            tenant_id = client.tenant_id
-        name = data_utils.rand_name(namestart)
-        result = client.create_router(name=name,
-                                      admin_state_up=True,
-                                      tenant_id=tenant_id)
-        router = result['router']
-        self.assertEqual(router['name'], name)
-        self.addCleanup(test_utils.call_and_ignore_notfound_exc,
-                        client.delete_router,
-                        router['id'])
-        return router
-
     def _update_router_admin_state(self, router, admin_state_up):
         kwargs = dict(admin_state_up=admin_state_up)
         router = self.routers_client.update_router(
diff --git a/manila_tempest_tests/tests/scenario/manager_share.py b/manila_tempest_tests/tests/scenario/manager_share.py
index af8f687..87e6fdc 100644
--- a/manila_tempest_tests/tests/scenario/manager_share.py
+++ b/manila_tempest_tests/tests/scenario/manager_share.py
@@ -120,7 +120,7 @@
             network=self.network,
             namestart="manila-share-sub",
             **subnet_ip_params)
-        router = self._get_router()
+        router = self.get_router()
         self._create_router_interface(subnet_id=self.subnet['id'],
                                       router_id=router['id'])
 
@@ -638,7 +638,7 @@
         if not client:
             client = self.routers_client
         if not router_id:
-            router_id = self._get_router()['id']
+            router_id = self.get_router()['id']
         client.add_router_interface(router_id, subnet_id=subnet_id)
         self.addCleanup(
             client.remove_router_interface, router_id, subnet_id=subnet_id)