Removed controller session cookie age setting

In AAP 2.5, the session age cookie is now managed in the gateway instead
of the controller.  Will need to be added back once we start adding in
separate gateway configuration as code.

common/setup.yml

@@ -285,6 +285,4 @@ controller_notifications:
       http_method: POST
       headers: {}
 
-controller_settings:
-  - name: SESSION_COOKIE_AGE
-    value: 180000
+...