Add enable_warnings_2 to example (#517)

Change-Id: I1a491bc4b993e877c7ec813d232354eb6b0db681

Author: devchas

google-ads-examples/src/main/java/com/google/ads/googleads/examples/remarketing/UploadStoreSalesTransactions.java

@@ -488,6 +488,7 @@ private void addTransactionsToOfflineUserDataJob(
           userDataJobOperations.size(),
           response.getPartialFailureError().getMessage());
 
+      // [START enable_warnings_2]
       // Checks if any warnings occurred and displays details.
       if (response.hasWarning()) {
         // Converts the Any in response back to a GoogleAdsFailure object.
@@ -498,6 +499,7 @@ private void addTransactionsToOfflineUserDataJob(
             System.out.printf(
                 "Encountered %d warning(s).%n", warningsFailure.getErrorsCount()));
       }
+      // [END enable_warnings_2]
     } else {
       System.out.printf(
           "Successfully added %d operations to the offline user data job.%n",