rtc_time: test agent timeouts

(cherry pick from commit 9258225ece5d6816ddf9a45e45fb694142c32761)

Break the test up into four, keeping each well below the 60 second
timeout for the test agents. Overhead for the splitting up is an
additional 10 seconds in order to complete all four of the tests
instead of one. typical single test completion is 22.5 seconds.

Change-Id: If8e9a6c7dfd505a9fbc73e9248be4eb2b61521e5
1 file changed