overlay: add tmo and att default LTE apns

Change-Id: Ic243e0f9a37bbb50fb8d3b4c598f7e6e7e663fce
Merge "overlay: add tmo and att default LTE apns" into cm-11.0
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_vendor_cm into temp