[etrecord] Implement generic fallback for GraphModuleSerializer.handle_call_function

Title says it all!

Implement the case where `node.target` is neither `torch._ops.OpOverload` or `torch._ops.HigherOrderOperator`, instead of throwing an exception.

Differential Revision: [D88216198](https://our.internmc.facebook.com/intern/diff/D88216198/)

[ghstack-poisoned]

Author: ssjia

exir/serde/export_serialize.py

@@ -546,7 +546,13 @@ def handle_call_function(self, node: torch.fx.Node):
                 metadata=self.serialize_metadata(node),
             )
         else:
-            raise SerializeError(f"Serializing {node.target} is not supported")
+            ex_node = Node(
+                name=node.name,
+                target=node._pretty_print_target(node.target),
+                inputs=self.serialize_hoo_inputs(node.args, node.kwargs),
+                outputs=self.serialize_hoo_outputs(node),
+                metadata=self.serialize_metadata(node),
+            )
 
         self.graph_state.nodes.append(ex_node)