Update preferred networks selection menu

Move "Use 2G Only" checkbox to "Network Mode" Menu
This menu consists of the followings in GSM Phone:
- 4G/LTE
- 3G
- 2G

4G/LTE means it's preferred, falling back to 3G, falling back to 2G.
3G means it's preferred, falling back to 2G.
2G means 2G only.

If config_prefer_2g is false, "2G Only" removes from Menu.
To use "LTE" menu, set config_enabled_lte true as mcc/mnc.
That means config_enabled_lte is false as default.
If set config_show4GForLTE true in SystemUI, display 4G instead of LTE.

In case of CDMA Phone with LTE,
- LTE
- 3G
- 1x
- Global
For (global) roaming of cdma, should set config_show_cdma true as mcc/mnc.

Bug: 10332749, 10783369
Change-Id: I74a9096f528bcd2a9a1162b53194ece653243bf7

Conflicts:

	res/values/strings.xml
	src/com/android/phone/MobileNetworkSettings.java
Merge branch 'berserk' of github.com:berserkaosp/packages_services_Telephony into berserk