Increase timeout waiting for OOM event to 10s from 3s
Increase timeout waiting for OOM event to 10s from 3s

We've seen it take over a second for the event to be emitted when the
CPU is under heavy load, so extend the test timeout.

[#163904164]

Co-authored-by: Giuseppe Capizzi <1968455d84ef56ceb93e8ec69a3034a6fe0ab9cc@pivotal.io>

cloudfoundry-incubator/guardian,cloudfoundry-incubator/guardian,cloudfoundry-incubator/guardian