change upstream URL for private search (#3270)

ansible/roles/kong-api/defaults/main.yml

@@ -100,6 +100,7 @@ lms_service_url: "http://lms-service:9000"
 cert_service_url: "http://cert-service:9000"
 cert_registry_service_url: "http://cert-registry-service:9000"
 content_service_url: "http://content-service:9000"
+search_service_url: "http://search-service:9000"
 report_service_url: "http://report-service:3030"
 opensaber_service_url: "http://opensaber-service:8080"
 program_service_url: "http://program-service:6000"
@@ -414,7 +415,7 @@ kong_apis:
 
   - name: compositePrivateSearch
     request_path: "{{ composite_service_prefix }}/v1/private/search"
-    upstream_url: "{{ knowledge_mw_service_url }}/v3/private/search"
+    upstream_url: "{{ search_service_url }}/v3/private/search"
     strip_request_path: true
     plugins:
     - name: jwt