Build Coupon UI - Create the coupon path (https://medium.com/@akexorcist/how-we-built-developer-friendly-coupon-ui-in-android-part-2-78933730d335)

CouponLayout.kt

val canvas: Canvas = /* ... */
val paint: Paint = /* ... */
val path = Path().apply {
    reset()
    moveTo(/* Start point */)                
    arcTo(/* Top right corner */)            // 1
    arcTo(/* Right edge semi circle */)      // 2
    arcTo(/* Bottom right corner */)         // 3
    arcTo(/* Bottom edge semi circle */)     // 4
    arcTo(/* Bottom left corner */)          // 5
    arcTo(/* Left edge semi circle */)       // 6
    arcTo(/* Top left corner */)             // 7
    arcTo(/* Top edge semi circle */)        // 8
    close()                                  
}
canvas.drawPath(path, paint)