Add Network Preference Bitmaps

To support conversion of the preferred network types
back to the network "class" types (really the RANs),
this change adds bitmaps for 2G, 3G, and 4G bitmaps
as well as for differentiating between 3gpp and 3gpp2
RATs.

Bug: 128572818
Test: manual
Change-Id: I25f41ad48eb4dc74c2cace80ccec4e1e954443f9