Telephony: Add getLteOnGsmMode() method (2/2)

Same functionality as the existing getLteOnCdmaMode, but for GSM
LTE devices.
Enable with the telephony.lteOnGsmDevice system property

From CM 10.0: Ibfb47ca608e51393b99d3308e0a6c66050b3f32e
- Moved getLteOnGsmModeStatic() to TelephonyManager.
Telephony: Add getLteOnGsmMode() method (2/2)

Same functionality as the existing getLteOnCdmaMode, but for GSM
LTE devices.
Enable with the telephony.lteOnGsmDevice system property

From CM 10.0: Ibfb47ca608e51393b99d3308e0a6c66050b3f32e
- Moved getLteOnGsmModeStatic() to TelephonyManager.

Conflicts:
	src/java/com/android/internal/telephony/BaseCommands.java
Fix restoring network mode preference on reboot

When a user sets the option to use only 2G networks (for GSM networks) or its
equivalent for CDMA networks, each reboot erases that setting. That forces
the user to re-select the same option after each boot.
This (very simple) patch fixes it.

Ported from CM9:
http://review.cyanogenmod.org/#/c/16245/

Change-Id: I7ec9e155fed9f57934d7a73936f2bf425c8297fe
Fix build
cdma: Restore SVDO after merge.

Allow evdo/ehrpd + voice simutaneously.
Use ro.ril.svdo=true

Change-Id: If7be25edc10f21680adbe3a059370d77a82ef076
telephony: set PROPERTY_DATA_NETWORK to data technology

The GSM SS is inaccurately setting the property to voice technology
instead of data technology (CDMA's SS is correct.)

Change-Id: I35a0a789bc06159f65325946e43f166f531bb1cc
Could not enable data connection

Could not enable the default type APN in below case:
1. Default apn exists, connect wifi
2. Delete default apn
3. Disconnect wifi

enableApnType won't reactivate default apn type when no
default apn exists. Add default apn criterium to avoid this.

Change-Id: Ic8699669e576e5d2140852f359e34ed6c3275633
Telephony: check if the provisioning apn is actually empty before

checking if they are equal.  Fixes cases where the stubbed apn
(empty) equal to the empty provisioning apn.

Fixes no IP issues on CDMA data types.

Change-Id: Id7bda83778f5ce59c87463c4d44fc5768dbc4a08
[1/3] opt_telephony: National Data Roaming

Credits: CyanogenMod

Linked commits:
        frameworks/base: https://gerrit.paranoidandroid.co/#/c/3654/
        services/Telephony: https://gerrit.paranoidandroid.co/#/c/3656/

Change-Id: I1cbb3dc5610a720fd5a7d7dfd35db513126d496f