Move GLOG_ constants into c10 namespace (#41504)
Summary:
Declaring GLOG_ constants in google namespace causes a conflict in C++ project that uses GLOG and links with LibPyTorch compiled without GLOG.
For example, see https://github.com/facebookresearch/ReAgent/issues/288
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41504
Reviewed By: kaiwenw
Differential Revision: D22564308
Pulled By: malfet
fbshipit-source-id: 2167bd2c6124bd14a67cc0a1360521d3c375e3c2
