Incorrect logging setup - duplicating root handlers

Stop adding the log handlers from the root logger to the logger specified via
the default_log_levels configuration setting. If the handler should dispatch
a event then it will do it once for the specified logger and once for root
logger thus duplicating the event.

Change-Id: I1a7880322ff53cbdf8048e1d805511ca76929ee3
Merge "Incorrect logging setup - duplicating root handlers"