test_streaming_pipeline_returns_expected_user_metrics_fnapi_it failed on latest PostCommit Py36

[damccorm]

https://builds.apache.org/job/beam_PostCommit_Python36/731/

Imported from Jira BEAM-8413. Original Jira may contain additional context.
Reported by: boyuanz.

[Abacn]

.close-issue not_planned