Maybe this will create what you want
paint.setColor(color); // set the color
paint.setStrokeWidth(size); // set the size
paint.setDither(true); // set the dither to true
paint.setStyle(Paint.Style.STROKE); // set to STOKE
paint.setStrokeJoin(Paint.Join.ROUND); // set the join to round you want
paint.setStrokeCap(Paint.Cap.ROUND); // set the paint cap to round too
paint.setPathEffect(new CornerPathEffect(10) ); // set the path effect when they join.
paint.setAntiAlias(true); // set anti alias so it smooths
🙂