How to convert a png file to xml resource by Android?

You can import a svg asset and convert it into a vector.

Click on new vector asset and you will have two options , psd and svg. Import your svg file and it will be stored as a xml file.

In current Android Studio version (3.6 rc1), you can import png image directly. File-> New-> Image Asset.

In the Asset Type, select Image, provide path to your image file and click on Next and Finish buttons.

Android Studio would do the conversion for you.