fix(docs): indent in docstring of key_averages (#53006)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/52742
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53006
Reviewed By: H-Huang
Differential Revision: D26725101
Pulled By: albanD
fbshipit-source-id: 867be12b0ee363a3c0ddcaf8cb4f6354dd4aa901
