type `DidDocumentMetadata`

`registry_api.v1.DidDocumentMetadata`

Field	Type	Description
created	Timestamp	Timestamp representing the DID document creation time.
updated	Timestamp	Timestamp representing the DID document last update time.

{
  "created": {
    "seconds": 0,
    "nanos": 0
  },
  "updated": {
    "seconds": 0,
    "nanos": 0
  }
}