allow Bazel to build without glog and gflags (#70850)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70850
We support both, so we want to ensure both continue to work.
ghstack-source-id: 146960552
Test Plan: Tested manually. A subsequent diff adds this test configuration to CI.
Reviewed By: malfet
Differential Revision: D33297464
fbshipit-source-id: 70e1431d0907d480c576239af93ef57036d5e4d7
