Handle restored purchases in iOS example app (flutter#4392)

Author: BeMacized

packages/in_app_purchase/in_app_purchase_ios/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 0.1.3+5
 
+* Updated example app to handle restored purchases properly.
 * Update dev_dependency `build_runner` to ^2.0.0 and `json_serializable` to ^5.0.2.
 
 ## 0.1.3+4

packages/in_app_purchase/in_app_purchase_ios/example/lib/main.dart

@@ -399,7 +399,8 @@ class _MyAppState extends State<_MyApp> {
       } else {
         if (purchaseDetails.status == PurchaseStatus.error) {
           handleError(purchaseDetails.error!);
-        } else if (purchaseDetails.status == PurchaseStatus.purchased) {
+        } else if (purchaseDetails.status == PurchaseStatus.purchased ||
+            purchaseDetails.status == PurchaseStatus.restored) {
           bool valid = await _verifyPurchase(purchaseDetails);
           if (valid) {
             deliverProduct(purchaseDetails);

packages/in_app_purchase/in_app_purchase_ios/pubspec.yaml

@@ -2,7 +2,7 @@ name: in_app_purchase_ios
 description: An implementation for the iOS platform of the Flutter `in_app_purchase` plugin. This uses the iOS StoreKit Framework.
 repository: https://github.com/flutter/plugins/tree/master/packages/in_app_purchase/in_app_purchase_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.1.3+4
+version: 0.1.3+5
 
 environment:
   sdk: ">=2.14.0 <3.0.0"