Add assertion message for full returned file info

Author: bnavigator

tests/integration/test_native_upload.py

@@ -530,7 +530,10 @@ def test_metadata_with_zip_files_in_package(self, credentials):
             ],
             key=lambda x: x["label"]
         )
-        assert files_as_expected == expected_files
+        assert files_as_expected == expected_files, (
+            f"File metadata not as expected: {json.dumps(files, indent=2)}"
+        )
+
 
     def test_too_many_zip_files(
         self,