[Torch] Cast timestamp type to int (#59712)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59712
When worker process fails in fb due to signal failure, the TerminationHandler writes error reply file. Recently the error reply file was changed for mast jobs. The Json value of ``timestamp`` is string, even though in the thrift struct it is int: https://fburl.com/diffusion/upa228u5
This diff adds support for casting str timestamp to int.
Test Plan: buck test mode/dev-nosan //caffe2/test/distributed/elastic/multiprocessing/errors:api_test
Reviewed By: suphoff
Differential Revision: D28995827
fbshipit-source-id: 333448cfb4d062dc7fe751ef5839e66bfcb3ba00
