This works as instead of passing *all* rooms to `record_sent_rooms` we
only need to pass rooms that were previously not in the LIVE state.
This came from a py-spy where we were spending ~10% CPU calling these
functions. Note that `record_sent_rooms` is a no-op for rooms that are
already in the `LIVE` state, so we only need to call them for
`PREVIOUSLY` or `INITIAL` rooms.
Erik Johnston