More data usage radio combinations, testing.

Offer Ethernet data when present, and better handling of devices
with various radio combinations.  Include "setprop" to help testing
in future.

Adopt new NetworkTemplate building in framework, and avoid crash
when AsyncTask finishes after Fragment is removed.

Bug: 5026016, 5029874
Change-Id: Ib7ab501d0111b9860a91c248193919663d47f2a2