Add new NetworkType for WIFI+CELLULAR+VPN transport

Define NT_WIFI_CELLULAR_VPN in enum NetworkType.
=>Indicates this network uses a WIFI+CELLULAR+VPN transport.

Bug: 143732914
Test: Manual test with statsd_testdrive
Change-Id: I1d43633705b69bf0111386630b2eebf394cb9366
1 file changed