provide memory format as Contiguous explicitly when calling to clone() (#28029)
Summary:
provide memory format explicitly when calling to clone():
```
clone(MemoryFormat::Contiguous); \\instead of clone()
```
This change is based on https://github.com/pytorch/pytorch/pull/27106
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28029
Differential Revision: D17937468
Pulled By: ifedan
fbshipit-source-id: 0a6a600af76fc616f88893e5db16aabd7981ce14
