jflte: add mpdecision to system group

Change-Id: Ic669a0eb87a300a278359a4963307c10413a440f
Reference: https://android.googlesource.com/device/lge/hammerhead/+/bf8fcfa71fd365add34a394cbe38828ce8a558fb%5E!/#F0
Merge https://github.com/CyanogenMod/android_device_samsung_jflte into kk-4.4