fix(managed_files.py): apply decoded file id transformation

tests/litellm/proxy/hooks/test_managed_files.py

@@ -0,0 +1,19 @@
+import json
+import os
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+sys.path.insert(
+    0, os.path.abspath("../../../..")
+)  # Adds the parent directory to the system path
+
+from litellm.proxy.hooks.managed_files import _PROXY_LiteLLMManagedFiles
+
+# def test_get_file_ids_and_decode_b64_to_unified_uid_from_messages():
+#     proxy_managed_files = _PROXY_LiteLLMManagedFiles()
+#     messages = [
+#         {
+#             "role": "user",
+#             "content": [