add channels last support for AvgPool2d on CPU (#48918)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48918
enable test case on AvgPool2d channels last for CPU
Test Plan: Imported from OSS
Reviewed By: glaringlee
Differential Revision: D25399466
Pulled By: VitalyFedyunin
fbshipit-source-id: 9477b0c281c0de5ed981a97e2dcbe6072d7f0aef
