By default Vcloud installs a certificate that is used for the Vcloud Federation feature. This Certificate expires after 1 year. If you dont use the Federation feature you can ignore this notification.

If you like to use federation in the future so you can login to Vcloud with 3rd party providers you can generate a new certificate by following these steps: In Vcloud go to Administration → Federation → click on regenerate

JT : FYI : https://secura.cloud/knowledge-base/renewing-a-vmware-vcloud-federation-certificate