add channels last for AdapativeMaxPool2d (#48920)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/48920
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D25399467
Pulled By: VitalyFedyunin
fbshipit-source-id: d9d2cc728cc7a18a26983e96d3c3e81a23659e89
