Are there any Android Drawable designers?
I faced the same problem and I've just released a little library on github that allow to export svg to drawable more quickly.
https://github.com/r3gis3r/svg2drawable
Hope can be useful for you.
For the sub-subset of rectangular ShapeDrawables there is a nice tool online at Angry Tools which allows one to edit a button's drawable:
I would suggest you using Vector Drawables, which are natively supported by Android 5.0+. There is an SVG to VectorDrawable Converter, so you can create SVG images in your favorite editor.
BetterVectorDrawable is the VectorDrawable implementation for Android 4.0+ with configurable fall-back behavior on Android 5.0+.
SVG to VectorDrawable Converter is the batch converter of SVG images to Android VectorDrawable XML resource files. Online version exists.
Links point to readmes, which provide enough information on how to use the lib and the converter.