FP3: Remove vendor RenderScript implementation.

 * RenderScript is deprecated on newer platforms and
   is being officially replaced.

 * On April 19, 2021, Google announced that RenderScript
   will be deprecated in Android 12, and recommended
   porting existing code to Vulkan.

   https://android-developers.googleblog.com/2021/04/android-gpu-compute-going-forward.html

Change-Id: I19460ef266a646b046f1e7d2f0b4eab7c48ae536