Autotest: Increase run timeout granularity

This CL modifies all references to max_runtime_hrs to instead be
max_runtime_mins. This includes the django models, rpc interfaces, the
cleanup timeout code, and the frontend java views.

The frontend java code will need to be recompiled once this commits to
prevent the frontend from breaking.

The cleanup timeout pathway has been adjusted to find all timedout jobs
by minute, and has been changed to run every 5 minutes vs every hour as
before.

BUG=chromium-os:36067
TEST=Ran on my local afe, ensure that jobs can still be created correctly,
     and jobs with short timeouts do indeed get aborted when expected.

Change-Id: Idfdeb3f1d4947d6b2e6b48127a31db535704e972
Reviewed-on: https://gerrit.chromium.org/gerrit/37827
Tested-by: Simran Basi <sbasi@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Reviewed-by: Simran Basi <sbasi@chromium.org>
Commit-Ready: Simran Basi <sbasi@chromium.org>
15 files changed