fix: request form builder missing arg

Author: srtaalej

json-logs/samples/api/slackLists.items.list.json

@@ -8,7 +8,7 @@
     {
       "id": "",
       "list_id": "",
-      "date_created": 12345,
+      "date_created": 0,
       "created_by": "",
       "updated_by": "",
       "fields": [

slack-api-client/src/main/java/com/slack/api/methods/RequestFormBuilder.java

@@ -2881,6 +2881,7 @@ public static FormBody.Builder toForm(SlackListsItemsInfoRequest req) {
 
     public static FormBody.Builder toForm(SlackListsItemsListRequest req) {
         FormBody.Builder form = new FormBody.Builder();
+        setIfNotNull("list_id", req.getListId(), form);
         setIfNotNull("limit", req.getLimit(), form);
         setIfNotNull("cursor", req.getCursor(), form);
         setIfNotNull("archived", req.getArchived(), form);