PR #9814 appears to cause failures in fnapi_runner tests on Windows

It appears that changes in
https://github.com/apache/beam/commit/d6bcb03f586b5430c30f6ca4a1af9e42711e529c cause test failures in Beam test suite on Windows, for example:

python setup.py nosetests \--tests apache_beam/runners/portability/portable_runner_test.py:PortableRunnerTestWithExternalEnv.test_callbacks_with_exception

does not finish on a Windows VM machine within at least 60 seconds but passes within a second if we change host_from_worker to return 'localhost' in [1].

[~violalyu] , do you think you could take a look? Thanks!
cc: [~chadrik] [~thw]

[1] https://github.com/apache/beam/blob/808cb35018cd228a59b152234b655948da2455fa/sdks/python/apache_beam/runners/portability/fn_api_runner.py#L1377.

Imported from Jira [BEAM-8646](https://issues.apache.org/jira/browse/BEAM-8646). Original Jira may contain additional context.
Reported by: tvalentyn.