Add size op in nnapi serializer (#52026)
Summary:
serializer didn't support aten::size
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52026
Test Plan: Torchvision Mobilenetv2 [script](https://pytorch.org/tutorials/prototype/nnapi_mobilenetv2.html) works. [Test](https://github.com/pytorch/pytorch/commit/ecfed07cc599b7c95e98d692984d47cbee769a85) to be merged after [this PR](https://github.com/pytorch/pytorch/pull/47521/files) is merged
Reviewed By: dreiss
Differential Revision: D26363133
Pulled By: axitkhurana
fbshipit-source-id: 772a6bea62bca69f8bba19c25c582a1734a70eb1
