Added static sleep to let subscriber and ONU delete process in OLT PON Disable/Enable scenario

Change-Id: Ic6456a2bcf8d7988c991b3cf5d0ce85c2f464463
diff --git a/libraries/utils.robot b/libraries/utils.robot
index b39e660..c332041 100755
--- a/libraries/utils.robot
+++ b/libraries/utils.robot
@@ -834,6 +834,8 @@
         # Remove Subscriber Access (To replicate ATT workflow)
         ...    AND    Wait Until Keyword Succeeds    ${timeout}    2s    Execute ONOS CLI Command use single connection
         ...    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}    volt-remove-subscriber-access ${of_id} ${onu_port}
+        # Additional Sleep to let subscriber delete process
+        ...    AND    Sleep    5s
         ...    ELSE
         ...    Run Keyword If    ${has_dataplane}    Run Keyword And Continue On Failure
         ...    Wait Until Keyword Succeeds    60s    2s
@@ -969,6 +971,8 @@
         ...    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}    volt-remove-subscriber-access ${of_id} ${onu_port}
         # Delete ONU Device (To replicate DT workflow)
         ...    AND    Delete Device    ${onu_device_id}
+        # Additional Sleep to let subscriber and ONU delete process
+        ...    AND    Sleep    10s
         ...    ELSE
         ...    Run Keyword If    ${has_dataplane}    Run Keyword And Continue On Failure
         ...    Wait Until Keyword Succeeds    60s    2s