Tensor method rename dims()->sizes() (#15246)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15246
Codemod generated with clangr shard mode, 25 files per diff,
Reviewed By: igorsugak
Differential Revision: D13470369
fbshipit-source-id: ce995beab7c64bebe8b234fb5e6d015940ec2952
