If Tier-1 with the tier-1-id is not already present, create a new Tier-1 instance.
If it already exists, update the tier-1 instance with specified attributes.
Reprocess Tier1 gateway configuration and publish updates to NSX controller
Reprocess Tier1 gateway configuration and configuration of related entities like Tier1 interfaces
and static routes, etc. Any missing Updates are published to NSX controller.