overwriteDefaultIcons function
Note: Do not change interpolation unless you end up with better results (see issue for result when using cubic interpolation) https://github.com/fluttercommunity/flutter_launcher_icons/issues/101#issuecomment-495528733
Implementation
void overwriteDefaultIcons(
IosIconTemplate template,
Image image, [
String iconNameSuffix = '',
]) {
final Image newFile = createResizedImage(template, image);
File(
iosDefaultIconFolder +
iosDefaultIconName +
iconNameSuffix +
template.name +
'.png',
)..writeAsBytesSync(encodePng(newFile));
}