Bug 1469676 - Reduce max-run-time for various build tasks; r=glandium

The max-run-time for tasks appears to have been mostly cargo
culted. In particular, a value of 36000 (10 hours) is quite absurd:
no single task takes that long to execute.

This commit reduces the max-run-time of several tasks to
more reasonable values. The goal here is to prevent
excessively long-running tasks. There is definitely room to
further tweak values to further mitigate long-running tasks. But
let's bite off the biggest chunk first, since that doesn't
require much mental effort.

There is a possibility I overshot on some of these tasks. If we
get timeouts, we can always increase the timeout again.

Differential Revision: https://phabricator.services.mozilla.com/D1716