Executors.newSingleThreadExecutor() is never used

[AlexTrotsenko]

https://github.com/android/camera-samples/blob/de8b23595d3156a21b6cba53a79b502a46c90ff0/CameraX-MLKit/app/src/main/java/com/example/camerax_mlkit/MainActivity.kt#L58

I see, that Executors.newSingleThreadExecutor() was added in the https://github.com/android/camera-samples/commit/dcaf84fa6f152fd90ad620348f6a2c26351b4462 by @donovanfm, but it's never used.

Was there an idea to use it instead of ContextCompat.getMainExecutor(this) ? If so - what's the pros/cons of such single thread executor ?