1. If a new brightness animation is started while an unrelated one is ongoing complete the old animation immediately. Unrelated means that the old and new animations apply to different devices (button, keyboard, or screen). 2. Do not interpret turning off the keyboard or button lights as turning off the screen in isScreenTurningOffLocked(). Fixes bug 6519847. Change-Id: I53a20951036bcdb793daeff84a9ebeed44be01fc