Add networkCreate API. Deprecate networkCreate[Physical/Vpn]

OEMs need VPN type information in Netd for customization. According to
stable AIDL rules, Netd can neither extend parameters in the existing
networkCreateVpn, nor add a new API with the identical name (function
overloading). Thus, add an extensible API which can create physical
network, virtual network, and so on. Deprecate networkCreatePhysical
and networkCreateVpn.

Bug: 171872481
Test: atest
Change-Id: I9094593c902d91d90a8210960c608f0a50f163ff