An event that triggers when a contact is updated.
The onContactUpdated() event handler runs when a
contact
is updated.
The received ContactUpdatedEvent object
contains information about the contact that was updated.
If a contact is updated as part of a merge,
metadata.originatedFrom is sent as "merge".
Otherwise, originatedFrom is omitted.
Note: Backend events don't work when previewing your site.
Information about the contact that was updated and metadata for the event.