Fix test boltnn test failure.

Summary: Context: D48288890

Reviewed By: tugsbayasgalan

Differential Revision: D48318520

fbshipit-source-id: 2f87c9e46e30f0876593f01c20d845684f6edd12

Author: zhxchen17

exir/serde/serialize.py

@@ -630,6 +630,10 @@ def deserialize(
 ) -> exir.ExportedProgram:
     exported_program_str = exported_program_bytes.decode("utf-8")
     exported_program_dict = json.loads(exported_program_str)
+    # Executorch tests save exported program on disk when we haven't
+    # provided any compatibility guarantees.
+    if "module_call_graph" not in exported_program_dict["graph_module"]:
+        exported_program_dict["graph_module"]["module_call_graph"] = []
     serialized_exported_program = export_serialize._dict_to_dataclass(
         schema.ExportedProgram, exported_program_dict
     )