We currently configure only TimeoutStartSec, but probably it's not
enough to prevent coredump timeout, since TimeoutStartSec is maximum
waiting time for service startup, and there is another directive to
specify maximum service running time (RuntimeMaxSec).
To fix the problem, we should specify RunTimeMaxSec and TimeoutSec (it
configures both TimeoutStartSec and TimeoutStopSec).
Fixes#5430Closes#12757
(cherry picked from commit bf27fdeaa2)
87e267213d