lights: Use NotificationManager to figure out LED capabilities

As of f/b change I7d627914b058861048071fc15776031c4152157f, there's
a more generic helper method in the notification service to get a
more unified (and extensible) list of what the on-device LEDs can
do. Move away from direct usage of the boolean resources.

Change-Id: Ib9a6f28dc52af722dac168ec219b790ad94d6a19