fix(Ads): Prevent playing the same ad twice (#7585)

Author: avelad

lib/ads/interstitial_ad_manager.js

@@ -461,8 +461,7 @@ shaka.ads.InterstitialAdManager = class {
               this.lastTime_ - roundDecimals(interstitial.startTime);
           if (difference > 0 &&
               (difference <= 1 || !interstitial.canJump)) {
-            if (difference > 1 && lastPlayedAd &&
-                !lastPlayedAd.pre && !lastPlayedAd.post &&
+            if (lastPlayedAd && !lastPlayedAd.pre && !lastPlayedAd.post &&
                 lastPlayedAd.startTime >= interstitial.startTime) {
               isValid = false;
             } else {