Fix AdaptiveAvgPool{2,3}d and AdaptiveMaxPool{2,3}d implementation (#35022)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35022
This PR fixes `AdaptiveAvgPool{2,3}d` and `AdaptiveMaxPool{2,3}d` implementation to match the Python API implementation. Particularly, `output_size` is changed to accept `c10::nullopt` in its elements, matching the Python API behavior.
**TODO**: cherry-pick this PR into v1.5 release branch.
Test Plan: Imported from OSS
Differential Revision: D20559890
Pulled By: yf225
fbshipit-source-id: ccddbd278dd39165cf1dda11fc0e49387c76dbef
