Convert the outer lockscreen ring to a shape drawable.

Saves 270dp^2 of pixel memory: 290K on mdpi, 650K on hdpi,
1.2MB on xhdpi. Multilockwave is still 60fps on crespo.

Bug: 5497875
Change-Id: Idf420e31741cf8d86d86813802b67c9a9f780f80
4 files changed