Update on "[ExecuTorch][#10447] Extend PyBundledModule with extension.BundledModule"

#10447

# Context

This issue is a step of #9638.

In #9638, we want to have `extension.Module` as the single source of implementation in `pybindings`, which means that `pybindings.PyModule` should use `extension.Module` rather than its own `pybindings.Module`.

# Proposal

Now that we have `extension.BundledModule` ready, we want to test it out by having our existing `PyBundledModule` to extend it, and let `verify_result_with_bundled_expected_output` to use it, so that we can test out the whole thing with https://github.com/pytorch/executorch/blob/fb45e19055a92d2a91a4d4b7008e135232cbb14b/devtools/bundled_program/test/test_end2end.py

Differential Revision: [D73564127](https://our.internmc.facebook.com/intern/diff/D73564127/)

[ghstack-poisoned]

Author: zhenyan-zhang-meta

devtools/bundled_program/bundled_program.cpp

@@ -267,7 +267,7 @@ ET_NODISCARD Error load_bundled_input(
       "testset_idx %zu is out of range [0, %u]",
       testset_idx,
       test_cases->size());
-  auto bundled_inputs = test_cases->Get(testset_idx)->inputs();
+  auto bundled_inputs = test_cases->Get(static_cast<flatbuffers::uoffset_t>(testset_idx))->inputs();
 
   for (size_t input_idx = 0; input_idx < method.inputs_size(); input_idx++) {
     auto bundled_input = bundled_inputs->GetMutableObject(input_idx);
@@ -372,7 +372,7 @@ ET_NODISCARD Error verify_method_outputs(
       testset_idx,
       test_cases->size());
   auto bundled_expected_outputs =
-      test_cases->Get(testset_idx)->expected_outputs();
+      test_cases->Get(static_cast<flatbuffers::uoffset_t>(testset_idx))->expected_outputs();
 
   if (bundled_expected_outputs->size() == 0) {
     // No bundled expected outputs, so we can't verify the method outputs.