Bugzilla

Ran the following (from a local clone of bigquery-etl):

```
for x in $(seq 11 21); do 
  ./script/copy_deduplicate \
    --project_id=moz-fx-data-shared-prod \
    --billing_project moz-fx-data-shared-prod \
    --only "firefox_installer_live.install_v1" \
    --parallelism=1 \
    --date=2021-03-${x}
done
```

The counts in the stable table are now higher for 2021-03-11 through 2021-03-19. There was no change for 2021-03-20. See https://sql.telemetry.mozilla.org/queries/78998/source for comparison of pref-backfill and post-backfill counts.

Ran the following (from a local clone of bigquery-etl):

```
for x in $(seq 11 21); do 
  ./script/copy_deduplicate \
    --project_id=moz-fx-data-shared-prod \
    --billing_project moz-fx-data-shared-prod \
    --only "firefox_installer_live.install_v1" \
    --parallelism=1 \
    --date=2021-03-${x}
done
```

The counts in the stable table are now higher for 2021-03-11 through 2021-03-19. There was no change for 2021-03-20. See https://sql.telemetry.mozilla.org/queries/78998/source for comparison of pre-backfill and post-backfill counts.