Notify on nightly test timeouts

[melinath]

Affected Resource(s)

• google_*

Issue Description

Timeouts in nightly tests can be easy to miss and cause uncertainty about release stability. We should set up notifications for timeouts if possible.

[SarahFrench]

Unassigning myself from this issue but leaving some info:

This issue dates from when all tests ran in a single build and the run duration kept growing as new tests were added. Now we have a build per service so there are more builds that each have shorted run times. Currently the longest running builds are ~8 hours long (Container/GKE service). All build configurations have a timeout of 12 hours set at the moment, which is the default. No timeout info is set in the TeamCity config code.