[autotest] Increase timeout for connecting TKO db.

Also log stats to counter tko_db_con_error if connection attempt timed out.

BUG=chromium:539984
TEST=None

Change-Id: I228493e83297b9894c285b472052b88a44864a1e
Reviewed-on: https://chromium-review.googlesource.com/304351
Commit-Ready: Dan Shi <dshi@chromium.org>
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Fang Deng <fdeng@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
2 files changed