High res icon and image asset studio

Depdeep accepted answer above is obviously correct. Yet the file can be also found straight from your project path. In my case it was:

...\AndroidStudioProject\App_name\app\src\main\ic_launcher-web.png

Go Drawable > New > Image Asset > Legacy tab > Click next to generate the icons. You'll find the 512 x 512 icon in the root of src > main folder with a name called ic_my_sample_icon-web.png. Just right-click on the icon and select Show in Files / Reveal in Finder