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: Id7668bbd05a9b02c22e7c549fac232fae02fc728
Reviewed-on: https://gerrit.chromium.org/gerrit/37479
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Ready: Simran Basi <sbasi@chromium.org>
Tested-by: Simran Basi <sbasi@chromium.org>
15 files changed