Uses the twilight service to determine the hours of
sunrise and sunset. Shortly after sunset or before sunrise
gradually start to apply a gamma correction factor to the
auto-brightness calculations to make the screen a little
dimmer at night.
The effect is relatively small and is mostly noticeable
in dark rooms. This is just a first pass at the algorithm,
we can tweak the adjustment later to ensure that it has even less
impact in moderate or bright environments.
Change-Id: Idf89022a5d0bb52975e04779352d53fa63371178
aa202a6dc3