Currently the aggregation key identifier length limit (https://wicg.github.io/attribution-reporting-api/#max-length-per-aggregation-key-identifier) is checked in both source and trigger registrations. As this limit is not for privacy and it's not persisted in the storage, we are removing this limit in trigger registrations. This is consistent with other fields in the trigger registrations, e.g. filters and scopes, whose size is only checked in source registrations, but not trigger registrations.