Update RenderScript build rules for rebase to LLVM r256229

http://b/26987366

- Use clang-2690385 to build RenderScript toolchain.
- Use armv7-linux-androideabi as the triple used to build RenderScript
  runtime libraries.

(cherry picked from commit 41f4b242e38c6f95fff133cfb6f07691f56f672b)

Change-Id: I50751f410a2f7c83532cec9b96c50d9afe1224c1
4 files changed