Fix OSC incorrect pressed alpha when low values are used

OSC would "light up" when the alpha value was low because of the value being coerced to an arbitrary range. Divide the alpha value by 3 instead.

app/src/main/java/emu/skyline/input/onscreen/OnScreenButton.kt

@@ -123,7 +123,7 @@ abstract class OnScreenButton(
 
     open fun render(canvas : Canvas) {
         val bounds = currentBounds
-        val alpha = if (isPressed) (config.alpha - 130).coerceIn(30..255) else config.alpha
+        val alpha = if (isPressed) config.alpha / 3 else config.alpha
         renderColors(drawable)
         drawable.apply {
             this.bounds = bounds