Drop the "--since" option on the "voltctl event listen" command due to
a possible bug in kafka sarama client consumer configuration that results
in timestamp of the received kafka message to default at "0001-01-01 00:00:00 +0000".
A jira VOL-3657 is created to track this issue.
The BBSIM alarm tests fail because the "--since" option specifies that all
alarms after the current time be displayed, but the timestamp on the kafka
message is default and the check fails.

Change-Id: I2821e6124fbcea76a81a4d05b9c00cebd8703b40
diff --git a/tests/functional/Voltha_AlarmTests.robot b/tests/functional/Voltha_AlarmTests.robot
index ffa7d08..8f413c3 100755
--- a/tests/functional/Voltha_AlarmTests.robot
+++ b/tests/functional/Voltha_AlarmTests.robot
@@ -462,7 +462,7 @@
     [Documentation]    Get the most recent alarm event from voltha.events
     [Arguments]    ${deviceEventName}    ${since}
     ${output}    ${raiseErr}    Exec Pod Separate Stderr   ${VOLTCTL_NAMESPACE}     ${VOLTCTL_POD_NAME}
-    ...    voltctl event listen --show-body -t 1 -o json -f Titles=${deviceEventName} -s ${since}
+    ...    voltctl event listen --show-body -t 1 -o json -f Titles=${deviceEventName}
     ${json}    To Json    ${output}
     ${count}    Get Length    ${json}
     # If there is more than one event (which could happen if we quickly do a raise and a clear),