Backfill draft status column using corrected regex

We had previously attempted to backfill this value, but had used a faulty regular expression. After cleaning up and restoring the data, we're now ready to rerun the data migration with the corrected regex.

Related to #337861 (closed)

Our story so far...

We started with !62627 (merged) but that caused timeouts in staging.

So then we moved it to a background migration in !63703 (merged) but saw a number of failed/timed out jobs.

So we next tried !67687 (merged) to rerun them, and in the process of confirming the timeout issue, discovered the faulty SQL regex.

So I cleaned up the data set in !70735 (merged).

...and now, I think, we're finally ready to get this done and shipped.