Add enabled networks selection menu

Move "Use 2G Only" checkbox to "Enabled networks" Menu
This menu consists of the followings in GSM Phone:
- GSM Only
- WCDMA and GSM
- LTE, WCDMA, and GSM
If config_prefer_2g is false, "2G Only" removes from Menu.

In case of CDMA Phone with LTE,
- CDMA
- LTE and CDMA
- Global Auto
- WCDMA and GSM
For (global) roaming of cdma, should set config_show_cdma true
as mcc/mnc.

Bug: 10332749, 10783369
Change-Id: I74a9096f528bcd2a9a1162b53194ece653243bf7