Use the least code to create Android camera preview by using Camera and Camera2 APIs.
- https://stackoverflow.com/questions/38535355/android-textureview-full-screen-preview-with-correct-aspect-ratio
- https://github.com/googlesamples/android-Camera2Basic
- https://developer.android.com/reference/android/hardware/camera2/package-summary
- https://developer.android.com/guide/topics/media/camera
- https://developer.android.com/reference/android/view/TextureView