Modify 3D example with light and bump shader.

Depends on what I assume the final version of https://skia-review.googlesource.com/c/skia/+/272646 will be
Change-Id: I53485c5f47e0fef120c8a1bd6d0620fddfb3cde9
Bug: skia:9866
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/272529
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
5 files changed