feat: Standardise the external channel user id and user name (#8802)

* feat: Standardize the external channel id and user name

* chore: add specs

* chore: add name space `social`

app/services/line/incoming_message_service.rb

@@ -139,7 +139,14 @@ class Line::IncomingMessageService
   def contact_attributes
     {
       name: line_contact_info['displayName'],
-      avatar_url: line_contact_info['pictureUrl']
+      avatar_url: line_contact_info['pictureUrl'],
+      additional_attributes: additional_attributes
+    }
+  end
+
+  def additional_attributes
+    {
+      social_line_user_id: line_contact_info['userId']
     }
   end