Added bbsim verfication for ONU software upgrade

Change-Id: I612c6c1abf956e45b83fcdb52e387cb8d931adcc
diff --git a/libraries/bbsim.robot b/libraries/bbsim.robot
index ffcad0d..73b3f1f 100755
--- a/libraries/bbsim.robot
+++ b/libraries/bbsim.robot
@@ -98,3 +98,11 @@
     ...    bbsimctl olt restartServer ${delay}
     Log     ${res}
     Should Be Equal as Integers    ${rc}    0
+
+Verify ONU Device Image On BBSim
+    [Documentation]    Validates the state of ONU in case of Image Upgrade
+    [Arguments]    ${namespace}    ${bbsim_pod_name}    ${onu}    ${internal_state}
+    ${res}     ${rc}=    Exec Pod And Return Output And RC    ${namespace}    ${bbsim_pod_name}
+    ...    bbsimctl onu list | grep ${onu} | awk '{print $6}'
+    Should Be Equal as Integers    ${rc}    0
+    Should Be Equal    ${res}    ${internal_state}