If set, indicates the action the long-running operation is
currently performing. The meaning of this value depends on the
operation being performed. Generally, the string is a short tag.
RESTORE to indicate that data is being restored to
the database. Before presenting the tag to a user, it must be
translated to a human-readable string. The strings in member
args provide additional info about the action being performed.
- "result": "RESTORE",
- "error": "Error message (present if an error occurred)."