Use GLOG logging prefixes (#40491)
Summary:
PyTorch should stop polluting global namespace with symbols such as `ERROR` `WARNING` and `INFO`.
Since `logging_is_not_google_glog.h` is a C++ header, define severity levels in namespace and add `GLOG_` prefix to match an unshortened glog severity levels.
Change `LOG` and `LOG_IF` macros to use prefix + namespaced severity levels.
Closes https://github.com/pytorch/pytorch/issues/40083
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40491
Test Plan: CI
Reviewed By: ezyang
Differential Revision: D22210925
Pulled By: malfet
fbshipit-source-id: 0ec1181a53baa8bca2f526f245e398582304aeab
