Notification Background redo the entire thing (2/2) BS side.

Moved everything outta a switch case and into a int of a listpreference.
Cleaned up the updatevisibilty
Reworked the custom image alpha into a seekbarpreference.
Removed all calls to helpers.restartsystemui as its no longer required.
Added a separate settings string to handle the color fill option making everything int's simplify's the process.

Signed-off-by: travp624 <travp624@gmail.com>