Add metered, roaming, and defaultNetwork info to NetworkTemplate.

This will allow data usage clients to query for and receive
callbacks on data usage matching these conditions.

Bug: 35142602
Test: atest FrameworksNetTests
Change-Id: I4d985a2734eeab7ee454c09cc2098b6b3c671c23
Merged-In: I4d985a2734eeab7ee454c09cc2098b6b3c671c23