[1/2] ElectronBeam: Add an alternative screen-off animation

Adds a "scale down" screen-off effect. This is one experiment to see
how we can become more creative to make some cool screen-off anims.

Change-Id: I5f364512792d5723d3a8745169abdddda5959b92
Merge "[1/2] ElectronBeam: Add an alternative screen-off animation" into android-4.4