In certain cases, the keepalived can take a few seconds to run/stop.
For this reason, the patch proposes a change to the tests, in which
instead of asserting that the process started/stopped, we'll wait a
short while until they do. This will cause failing tests to not fail
simply because it took a few extra CPU cycles to run.
Change-Id: I497ef32651fbb68bf49e172543f9675f6279df4b
(cherry picked from commit 59bb1ecfb0)