Support selecting non-INTERNET networks as underlying networks

This commit allows VCN to select underlying Cell networks
according to caller configured network capabilities instead
of always only selecting INTERNET networks as underlying
networks.

This commit also makes sure that if all of the network candidates
fail to match caller configured network templates, VCN can still
select an INTERNET network as a fallback but will never select
a non-INTERNET network.

Bug: 245618320
Test: FrameworksVcnTests(new tests), CtsVcnTestCases
Change-Id: I6eca0331e4bc6804a500fbed9909bb91b1e80d2d