[VOL-3258] update Validate OLT keyword

Change-Id: I16f926bb969bafe3c86962d0b7d3e6bf61e819ee
diff --git a/libraries/utils.robot b/libraries/utils.robot
index 17466a2..47c9ce6 100644
--- a/libraries/utils.robot
+++ b/libraries/utils.robot
@@ -267,7 +267,7 @@
     ...    Validate OLT Device    PREPROVISIONED    UNKNOWN    UNKNOWN    ${olt_device_id}
     Sleep    5s
     Enable Device    ${olt_device_id}
-    Wait Until Keyword Succeeds    180s    5s
+    Wait Until Keyword Succeeds    250s    5s
     ...    Validate OLT Device    ENABLED    ACTIVE    REACHABLE    ${olt_serial_number}
     ${logical_id}=    Get Logical Device ID From SN    ${olt_serial_number}
     Set Suite Variable    ${logical_id}