Date or number of days the customer's tier upgrade or downgrade is valid till. If manualSlabActionValidity = FIXED_DURATION: Provide a numerical value. For example to extend the expiry by 15 days, provide this value as 15. If manualSlabActionValidity = SPECIFIC_DATE: Provide the date till when the tier is valid in YYYY-MM-DD format. For example to extend the expiry till 20th April, 2025, provide this value as 2025-04-20.