[autotest] Increase stateful_update timeout

This is to accommodate the occasionally network issue in the lab. The lab
devservers sometime are overloaded and the slow network can cause paygen runs
to timeout.

BUG=chromium:561036
TEST=None

Change-Id: I5d60319bc405caab2420bfc3d6ad22a79c8e0271
Reviewed-on: https://chromium-review.googlesource.com/323409
Trybot-Ready: Dan Shi <dshi@google.com>
Tested-by: Dan Shi <dshi@google.com>
Reviewed-by: Kevin Cheng <kevcheng@chromium.org>
1 file changed