Fix lift_constant_tensor_pass to make sure constants are not inserted in the state dict (#2558)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/2558

Currently in `lift_tensor_constant_pass` the lifted constants are being placed in the state dict which is the wrong place for them. They should be inserted in the `constants` section of the `ExportedProgram` which this diff addresses.

Reviewed By: angelayi

Differential Revision: D55175415

fbshipit-source-id: afe7f4df94f89de6d0c43dab824c498567a6b21f