Updated comments within the code sample.

PiperOrigin-RevId: 862911137

Author: Nicholas Ventimiglia

java/NextGenExample/app/src/main/java/com/example/snippets/InterstitialAdSnippets.java

@@ -68,6 +68,7 @@ public void onAdFailedToPreload(String preloadId, LoadAdError adError) {
           @Override
           public void onAdsExhausted(String preloadId) {
             Log.i(TAG, "Interstitial preload ad " + preloadId + " is not available");
+            // [Important] Don't call ad preloader start() or pollAd() from onAdsExhausted.
           }
 
           @Override

kotlin/NextGenExample/app/src/main/java/com/example/snippets/InterstitialAdSnippets.kt

@@ -62,6 +62,7 @@ private class InterstitialAdSnippets {
 
         override fun onAdsExhausted(preloadId: String) {
           Log.i(TAG, "Interstitial preload ad $preloadId is not available")
+          // [Important] Don't call ad preloader start() or pollAd() from onAdsExhausted.
         }
 
         override fun onAdPreloaded(preloadId: String, responseInfo: ResponseInfo) {