Add new WaveView widget to framework and integrate into LockScreen.

This adds a new "Energy Wave" widget to the internal widgets and
integrates it into LockScreen.

ValueAnimator needed a slight modification since it expects to
be run inside of Activities with a Looper. Additionally, this adds
an API, removeAllUpdateListeners(), which is needed to properly
recycle ValueAnimator objects.

Some minor code cleanup and UI tweaks after review.

Changed delay timeout from 1.3s to 0.5s.

Change-Id: Ibcf015e61fa8ba79d62f2019f1b29ace7caa00c8