LineageParts: Add notification brightness dialog

*) In the past, we added our brightness dialog to SystemUI.

*) Move and rework it here in LineageParts to shrink frameworks changes.

Adapted from the original frameworks/base commit:

Author: Adrian DC <radian.dc@gmail.com>
Date:   Tue Aug 18 19:33:18 2015 +0200
    frameworks/base: Lights notifications brightness support
    Implement the support of an overall brightness control for the LEDs.
    Change-Id: I1c0de01b1c6a2a2cf1432028a2e69f90b2373b2c

Change-Id: I425cc0747fe477d285d34eb2155565670bebf509