Framework: Add alternative screen-off animations (1/2)

Not everyone is keen on the electron beam screen-off animation. This allows
users to choose an alternative animation:

- Fade out
- Electron beam (default)
- Scale down

PS1: Update authorship
PS2: Fix derp

Change-Id: I060d02caf73e771135eb8ef36f2dd0000d278fc7

Conflicts:
	services/java/com/android/server/power/DisplayPowerController.java