util: pass invalidSubtypeIndex instead of trimmedSubtype to error
Followup from: #49711
The error ERR_INVALID_MIME_SYNTAX expects the invalid index which wasn't being passed.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Followup from: #49711
The error ERR_INVALID_MIME_SYNTAX expects the invalid index which wasn't being passed.