Mobile Network Battery Saver Mode
When idle (screen off) switching to  2G can help extend battery life as 2G generally uses less power than 3G or LTE. + 30 seconds after screen turns off, set network type to 2G + If a music player is active (playing), do not set network to 2G + When device is unlocked, reset to orignial network type Settings -> More -> Mobile Networks -> Battery saving mode

Change-Id: I014adc38ce95e64a92da970683665052ecf98fa3
Signed-off-by: Carlos Jesús <xxx.reptar.rawrr.xxx@gmail.com>