Migrate executorch examples to use export_for_training

Differential Revision: D62142608

Pull Request resolved: #5036

Author: tarun292

examples/models/test/test_export.py

@@ -29,7 +29,7 @@ def collect_executorch_and_eager_outputs(
         Returns a tuple containing the outputs of the eager mode model and the executorch mode model.
         """
         eager_model = eager_model.eval()
-        model = torch._export.capture_pre_autograd_graph(eager_model, example_inputs)
+        model = torch.export.export_for_training(eager_model, example_inputs).module()
         edge_model = export_to_edge(model, example_inputs)
 
         executorch_prog = edge_model.to_executorch()