title: Admob is not displaying ads when using Webview in IOS
body: <p>I'm developing a basic hybrid app with IOS Xcode. In app I have a UIWebview and a bottom toolbar with buttons. When user click toolbar buttons, I want to display interstitial ads and changing webview url. But ads is not displaying with message of 'Ads wasn't ready'. </p>
  
  <p>If i remove webview, ads is coming correctly. </p>
  
  <p>So why ads is not coming with webview? I have same android app on Google Play and it is working fine. </p>
  
  <pre><code>import UIKit
  import GoogleMobileAds
  class ViewController: UIViewController {
  
  var interstitial:   GADInterstitial!  
  
  @IBOutlet weak var webView: UIWebView!
  
  var phoneLang = "en"
  
  @IBAction func historyBtn(_ sender: Any) {
      displayAds()
     //todo: set webview url to go history page
    }
  
  @IBAction func favoritesBtn(_ sender: Any) {
      displayAds()
      //todo: set webview url to go favorites page
  }
  override func viewDidLoad() {
      super.viewDidLoad()
  
      phoneLang = NSLocale.preferredLanguages[0]
  
      let index = phoneLang.index(phoneLang.startIndex, offsetBy: 2)
      phoneLang = phoneLang.substring(to: index)        
      UserDefaults.standard.register(defaults: ["UserAgent": "MobileApp"])
  
      let xurl = URL(string: "https://www.sozcukcevir.com")
      let request = URLRequest(url: xurl!)        
      webView.loadRequest(request)        
      createAds()
  }
  
  override func didReceiveMemoryWarning() {
      super.didReceiveMemoryWarning()
      // Dispose of any resources that can be recreated.
  }
  
  
  fileprivate func createAds() {
      createAndLoadInterstitial()        
  }
  
  fileprivate func displayAds() {        
      if interstitial.isReady {
          interstitial.present(fromRootViewController: self)
      } else {
          print("Ad wasn't ready")
      }       
  }
  
  fileprivate func createAndLoadInterstitial() {
      interstitial = GADInterstitial(adUnitID: "ca-app-pub-5181306594932785/7917067758")
      let request = GADRequest()        
      request.testDevices = [ kGADSimulatorID, "2077ef9a63d2b398840261c8221a0c9a" ]
      interstitial.load(request)
    } 
  }
  </code></pre>