Add manual simple retry to ECR login (#71287)
Summary:
Current retry with AWS_MAX_ATTEMPTS does not seem to work as we still get failures https://github.com/pytorch/pytorch/runs/4806177738?check_suite_focus=true
This should hopefully alleviate
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71287
Reviewed By: malfet, seemethere
Differential Revision: D33573788
Pulled By: janeyx99
fbshipit-source-id: 300fde9a9fa5a2da3e9d18b7989a3676500d8011
