Adding sleep timers for solving ATT service instance recreation issue

Change-Id: Ic69d558b495f87b6f8129b082d6aba35be3b9a4c
diff --git a/src/test/cord-api/Tests/WorkflowValidations/ATT_Test001.robot b/src/test/cord-api/Tests/WorkflowValidations/ATT_Test001.robot
index dc36226..9e15686 100644
--- a/src/test/cord-api/Tests/WorkflowValidations/ATT_Test001.robot
+++ b/src/test/cord-api/Tests/WorkflowValidations/ATT_Test001.robot
@@ -387,10 +387,11 @@
     [Documentation]    Clean up all XOS objects and reinstall voltha after OLT reboots
     Wait Until Keyword Succeeds    60s    2s    Clean Up Objects    ${VOLT_SUBSCRIBER}
     Wait Until Keyword Succeeds    60s    2s    Clean Up Objects    ${ATT_WHITELIST}
+    Sleep    20s
     Wait Until Keyword Succeeds    30s    2s    Validate Subscriber Count    0
     Sleep    10s
     Wait Until Keyword Succeeds    60s    2s    Clean Up Objects    ${VOLT_DEVICE}
-    Sleep    15s
+    Sleep    20s
     Wait Until Keyword Succeeds    60s    2s    Clean Up Objects    ${ATT_SERVICEINSTANCES}
     Wait Until Keyword Succeeds    120s    10s    Check Remote System Reachability    False    ${olt_ip}
     Wait Until Keyword Succeeds    120s    10s    Check Remote System Reachability    True    ${olt_ip}