Telephony: Add getLteOnGsmMode() method (1/2)

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.
Framework: Quick Settings customization (Part 2 of 2) WIP!

This commit will alow loading the Quick Settings tiles layout from
a layout that is configured in Settings.

Patchset 3 - Restore Settings tile to AOSP location

Change-Id: Id4e4353dee68b8ca434dfa64d1f88737792a2e28

Conflicts:
	core/java/android/provider/Settings.java
Revert "SystemUI: Open Quick Settings panel if there are no active notifications"

This reverts commit 0031e6c3a1d6d2796d01430585d8d52d9b876552.

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

Change-Id: I6981416a8aa769663f471f2a536196af7ee7e70d