Update default controller name

Change the default value of `controller_name` from `gateway.api7.io/api7-ingress-controller` to `apisix.apache.org/api7-ingress-controller` to reflect the updated domain.

Author: dspo

test/e2e/framework/manifests/ingress.yaml

@@ -337,7 +337,7 @@ data:
   config.yaml: |
     log_level: "debug"
 
-    controller_name: {{ .ControllerName | default "gateway.api7.io/api7-ingress-controller" }}
+    controller_name: {{ .ControllerName | default "apisix.apache.org/api7-ingress-controller" }}
 
     leader_election_id: "api7-ingress-controller-leader"
 ---