[autotest] Add logging to db_cleanup.py

Take less than 20 seconds to delete 1 month data
from x86-mario shard with ~80,000 rows in afe_jobs
and ~110,000 rows in afe_special_tasks.

TEST=Run the script
BUG=chromium:455486
CQ-DEPEND=CL:222598

Change-Id: If8b58add15eb533f76d277b75c1100ffbe1a680a
Reviewed-on: https://chromium-review.googlesource.com/259030
Reviewed-by: Mungyung Ryu <mkryu@google.com>
Reviewed-by: Fang Deng <fdeng@chromium.org>
Commit-Queue: Fang Deng <fdeng@chromium.org>
Tested-by: Fang Deng <fdeng@chromium.org>
1 file changed