add type annotations to torch.nn.modules.normalization (#49035)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/49034
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49035
Test Plan:
Imported from GitHub, without a `Test Plan:` line.
Force rebased to deal with merge conflicts
Reviewed By: zhangguanheng66
Differential Revision: D25767065
Pulled By: walterddr
fbshipit-source-id: ffb904e449f137825824e3f43f3775a55e9b011b
