only run example on Android

packages/interactive_media_ads/example/lib/main.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_driver/driver_extension.dart';
 import 'package:interactive_media_ads/interactive_media_ads.dart';
@@ -22,7 +23,15 @@ const String _adTagUrl =
     'https://pubads.g.doubleclick.net/gampad/ads?iu=/21775744923/external/single_preroll_skippable&sz=640x480&ciu_szs=300x250%2C728x90&gdfp_req=1&output=vast&unviewed_position_start=1&env=vp&impl=s&correlator=';
 
 void main() {
-  runApp(const MaterialApp(home: AdExampleWidget()));
+  runApp(
+    MaterialApp(
+      // TODO(bparrishMines): Remove this check once the iOS implementation
+      // is added.
+      home: defaultTargetPlatform == TargetPlatform.android
+          ? const AdExampleWidget()
+          : Container(),
+    ),
+  );
 }
 
 /// Example widget displaying an Ad during a video.