TestStream.testFirstElementLate gives wrong answer on SamzaRunner

[damccorm]

https://ci-beam.apache.org/job/beam_PostCommit_Java_ValidatesRunner_Samza_PR/105/testReport/junit/org.apache.beam.sdk.testing/TestStreamTest/testFirstElementLate/

Expected: iterable with items [] in any order
     but: no match for: "late"
	at org.apache.beam.sdk.testing.PAssert$PAssertionSite.capture(PAssert.java:174)
	at
org.apache.beam.sdk.testing.PAssert.that(PAssert.java:416)
	at org.apache.beam.sdk.testing.PAssert.that(PAssert.java:408)
	at
org.apache.beam.sdk.testing.TestStreamTest.testFirstElementLate(TestStreamTest.java:258)

Imported from Jira BEAM-12035. Original Jira may contain additional context.
Reported by: kenn.