Request a sample to record OpenGL ES and Vulkan app

[Grafika's RecordFBOActivity](https://github.com/google/grafika/blob/master/app/src/main/java/com/android/grafika/RecordFBOActivity.java) contains a sample to record video from a OpenGL ES texture/fbo with `MediaCodec` and some OpenGL ES APIs. Android NDK supports `MediaCodec` APIs too, and it's better if there is an official out-of-box sample to do similar things with Android NDK APIs for OpenGL ES content and Vulkan content.

Start by reading Grafika's RecordFBOActivity.java, which demonstrates recording OpenGL ES texture/FBO content with MediaCodec. Define the scope of an official Android NDK sample covering MediaCodec with OpenGL ES and Vulkan content; done would be a complete out-of-box sample for those APIs.

Written by the indexing model from the issue text.