Fix Copyright Headers in python and codegen sdk

Summary: As in title

Reviewed By: stcheng

Differential Revision: D70584406

fbshipit-source-id: 098745a3feb88a901d791257dd0b873245e0d958

Author: satwikareddy3

config.json.example

@@ -1,3 +1,10 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
+
 {
   "app_id": "<YOUR_APP_ID>",
   "app_secret": "<YOUR_APP_SECRET>",