Reenables the testr per test timeout

This change reenables the testr per test timeout, but set the value to
10 minutes, a gate job take 5-8 minutes, so test should not take more
than 10 minutes.

Change-Id: Ifccef9040529ec1a0b21076ed17d91a4f9737096
Merge "Reenables the testr per test timeout"