Calling connect() will erase the mark set by the host resolver code because the
explicitlySelected bit of the Fwmark isn't set. It's by design that the
explicitlySelected bit isn't set as this facilitates falling through to other
routing rules if the selected network doesn't provide a route to the DNS server
as may be the case with VPNs.
Change-Id: I60ba7c754194ead97df3ac6a6c5b3db1f446dac8