[VOL-4155] Added keyword to wait for a particular device to be recognized as an OLT in ONOS, needed in the multi-stack scale test

Change-Id: I6d2442b24d55af489b1c4847a21d82cee31cdb4a
diff --git a/tests/bbsim/Voltha_BBSimTests.robot b/tests/bbsim/Voltha_BBSimTests.robot
index 567a4bc..15769f0 100644
--- a/tests/bbsim/Voltha_BBSimTests.robot
+++ b/tests/bbsim/Voltha_BBSimTests.robot
@@ -163,8 +163,8 @@
     # Perform OLT SoftReboot test
     ${olt_device_id}=    Get OLTDeviceID From OLT List    ${olt_serial_number}
     Reboot Device    ${olt_device_id}
-    Wait Until Keyword Succeeds    ${timeout}    2s    Device Is Available In ONOS
-        ...    http://karaf:karaf@${ONOS_REST_IP}:${ONOS_REST_PORT}    ${of_id}     false
+    Wait Until Keyword Succeeds    120s    2s    Device Is Available In ONOS
+    ...    http://karaf:karaf@${ONOS_REST_IP}:${ONOS_REST_PORT}    ${of_id}     false
     Run Keyword And Continue On Failure    Wait Until Keyword Succeeds    360s    5s
     ...    Validate OLT Device    ENABLED    ACTIVE
     ...    REACHABLE    ${olt_serial_number}