[QS] Add contentDescription and stateDescription to tile

These values were missing from the initial implementation. Since the
states are broken out from the way the old tile defined them, they're
generally simpler to see here. Mostly the content description is the
same as the underlying flow's description prepended by "Internet,".

Note that ethernet didn't have a content description defined in the old
tile impl. It's been added here.

Test: InternetTileViewModelTest
Test: manually testing different connections

Fixes: 299292270
Change-Id: Ieb16b594d235f8144014bc88dc3c565153661a07