Fix iOS ImageViewer example with Compose 1.4.3 and Kotlin 1.9.0 (#3502)

examples/imageviewer/shared/src/iosMain/kotlin/example/imageviewer/platform.ios.kt

@@ -17,6 +17,7 @@ import platform.Foundation.CFBridgingRelease
 import platform.UIKit.UIApplication
 import platform.UIKit.UIImage
 
+@OptIn(ExperimentalForeignApi::class)
 private val iosNotchInset = object : WindowInsets {
     override fun getTop(density: Density): Int {
         val safeAreaInsets = UIApplication.sharedApplication.keyWindow?.safeAreaInsets