Has anyone noticed the latest version of GCM (4.12.3) causing significant power drain on their phones? Looking further into it, is seems as though GCM is keeping the device in a perpetual 'awake' state, despite the screen being off, and Bluetooth/Internet being OFF, with no device connected. Have manually downgraded to v4.10, and is seems to have resolved this. Am running Android 5.0.1 with Galaxy S5.