Pretty much what the title says. I have 2 png's outside of pure xml files for vector drawables and I'm using the vector drawable support library.
vectorDrawables.useSupportLibrary = true
VectorDrawableCompat generates PNGs at compile time.
It's neccesary, because older APIs (<19) do not support vector drawables.
For not getting the PNGs, you must set minSDK to 21.