fix(Ads): Fix ad position by default (#7659)

Regression of
70257ff

Author: avelad

lib/ads/interstitial_ad_manager.js

@@ -255,10 +255,10 @@ shaka.ads.InterstitialAdManager = class {
     this.lastPlayedAd_ = null;
     if (!this.usingBaseVideo_) {
       this.video_.loop = false;
-      this.video_.style.height = '';
-      this.video_.style.left = '';
-      this.video_.style.top = '';
-      this.video_.style.width = '';
+      this.video_.style.height = '100%';
+      this.video_.style.left = '0';
+      this.video_.style.top = '0';
+      this.video_.style.width = '100%';
     }
   }
 
@@ -573,10 +573,10 @@ shaka.ads.InterstitialAdManager = class {
           this.baseVideo_.currentTime += interstitial.resumeOffset;
         }
         this.video_.loop = false;
-        this.video_.style.height = '';
-        this.video_.style.left = '';
-        this.video_.style.top = '';
-        this.video_.style.width = '';
+        this.video_.style.height = '100%';
+        this.video_.style.left = '0';
+        this.video_.style.top = '0';
+        this.video_.style.width = '100%';
       }
     }