Skip hostname verification when using insecure factory

If the factory was obtained by calling getInsecure(), calls to
createSocket() should skip hostname verification (along with all of the
other skipped safety checks.)

This change slightly relaxes the too-strict checking that was introduced
in change 7fc93c36.

Bug: 2834174
Change-Id: Iab7ef861ad0ca727f82ee8cdb78b89b9e835740d