roachtest: deflake online restore recovery roachtest

The online restore recovery roachtest would very occasionally flake due
to it detecting the download job having succeeded. It turns out that the
download job was not succeeding, but to find the job, we match on the
description containing "Background Data Download", which the GC job that
runs to cleanup after download contains. So if the download job failed
fast enough, the query to find the download job would match on the GC
job instead. This patch updates the query to only look for restore jobs
instead.

Fixes: #151973

Release note: None

Author: kev-cao

pkg/cmd/roachtest/tests/mixed_version_backup.go

@@ -2673,7 +2673,13 @@ func (d BackupRestoreTestDriver) getORDownloadJobID(
 	ctx context.Context, l *logger.Logger, rng *rand.Rand,
 ) (int, error) {
 	var downloadJobID int
-	if err := d.testUtils.QueryRow(ctx, rng, `SELECT job_id FROM [SHOW JOBS] WHERE description LIKE '%Background Data Download%' ORDER BY created DESC LIMIT 1`).Scan(&downloadJobID); err != nil {
+	if err := d.testUtils.QueryRow(
+		ctx,
+		rng,
+		`SELECT job_id FROM [SHOW JOBS]
+		WHERE description LIKE '%Background Data Download%' AND job_type = 'RESTORE'
+		ORDER BY created DESC LIMIT 1`,
+	).Scan(&downloadJobID); err != nil {
 		return 0, err
 	}
 	return downloadJobID, nil