How do I convert pngs directly to android vector drawables?

Ok, so you can convert PNG to Android vector drawable following these steps

• Step 1:
  Convert PNG to SVG (Scalable Vector Graphics)

https://www.autotracer.org/

Or you can use any online converter of your choice

• Step 2:
  Use the generated SVG in step 1 and convert it to Android vector drawable using this link
  http://inloop.github.io/svg2android/

http://a-student.github.io/SvgToVectorDrawableConverter.Web/

Alternatively you can also use Android studio to generate Vector drawables from SVG generated in Step 1.

• Inside Android studio, right click on your drawable folder
  New > Vector Asset

This will open up the Android studio Vector asset generator.
Select a local SVG file (the one you generated online)

You can also refer to this post
https://stackoverflow.com/a/35402459/6142219