Switch from networkCreate[Physical/Vpn] to networkCreate

networkCreatePhysical and networkCreateVpn are non-extensible. In order
to pass OEM requested VPN type to Netd, we need to migrate to
networkCreate API.

Modify test code accordingly since networkCreatePhysical and
networkCreateVpn have been deprecated on Netd.

Bug: 171872481
Test: atest FrameworksNetTests
atest atest HostsideVpnTests

Change-Id: I50ab8615346c49559c16e815482e7804a1e765c8