Settings: Option to enable Notification Light when screen is on [2/2]

This makes it possible to enable the Notification LED even when the screen is on

Conflicts:
	res/values/liquid_strings.xml

Change-Id: I765499803266b75ac3845203873badc2be7a8c67
[2/2] TrafficMeter: added option for auto-hiding on inactivity

Together with inactivity threshold

Thanks to @C3C0 for the code

Network traffic monitor: add summary to auto hide

also fix disabling autohide options when monitor is disabled

Change-Id: I2e88b946bc6fd2c3e4dbe205e47fbfcd66a68e9f