Allow creating EAP_TLS network without specifying Phase2.None

Phase2 isn't required for EAP_TLS networks, and it is possible
for a developer to miss it. We are requiring it for internal
book keeping - so this change just sets Phase2 to 'None' when
EAP_TLS is set on the configuration.

Bug: 17043082
Change-Id: I5a8e0a3a236d0dfd1295584de55d5b9a1b76b483