Simplify Shader.setLocalMatrix.

Previously, calling setLocalMatrix updated any Paint that had the
Shader attached. This depended on deprecated behavior in Skia. Use
new Skia APIs, and do not modify any Paints that use the Shader.

In addition, update callers to call setShader (again) after modifying
the Shader.

Sample app at ag/499573 for testing.

Depends on I673801444f0a8fd4f192b5b7effdde1aa83e702b in external/skia.

BUG:14315916
Change-Id: I3c3316377874e89fccc85afb864bc038b0ef3890