Instead of creating daemon threads using the threads module directly
use our small utility file to create the daemon thread on our behalf
and set the appropriate attributes to ensure it's a daemon thread.
This change replaces the existing locations where we were doing this
manually and uses the threading_utils helper function uniformly instead.
Change-Id: I535cee8a63407f753cf812df53c4f5bc83e0c9ae
c543dc2066