Properly skip distributed tests when distributed module is not built (#52945)
Summary:
Currently there is some code that intends to skip distributed tests if
the distributed module is not built. However, they are missing in some
test files; and in some other test files they are checked after
distributed module is imported, which leads to failure. This is
generating a lot of headaches when testing minimal builds locally.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52945
Reviewed By: anjali411
Differential Revision: D26848241
Pulled By: ezyang
fbshipit-source-id: 983a848844add40869a86f3c9413503a3659b115
