Settings: Slims ElectronBeam get some love (2/2)

Features:
- You can select different crt off animation modes if device overlay does not disable it at all
- disabled
- always horizontal (stock behaviour)
- always vertical (screen collapse from left and right to the middle)
- orientation dependent (means portrait = horizontal animation, landscape = vertical animation)
- some minor fixes/code style improvements to 4.3 implementation

Change-Id: Ie47304020949e8a3bbc91957bfb9de9da9ccdcdf