Move authorized flag to labels in metadata.yaml (#8141)

Author: scholtzan

sql/moz-fx-data-shared-prod/firefox_desktop/newtab_content_live/metadata.yaml

@@ -11,4 +11,5 @@ workgroup_access:
 - role: roles/bigquery.dataViewer
   members:
   - workgroup:mozsoc-ml/service
-authorized: true
+labels:
+  authorized: true