Revert "Revert "Revert "Halo: Add master switch to disable Halo (2/2)"""

This reverts commit 95be0e6263dec47b272088060d103e12b01bcf78.
Revert "Brightness slider - (2/2)"

This reverts commit ee52b6d39895cfe3c8559536c2b8f6915e0da48a.