Android: Confirm pending purchases

There seems to be a race condition which results in some purchases not
being confirmed.

lib/iap.dart

@@ -15,6 +15,7 @@ import 'package:gitjournal/utils/logger.dart';
 class InAppPurchases {
   static Future<void> confirmProPurchaseBoot() async {
     clearTransactionsIos();
+    confirmPendingPurchases();
 
     if (Features.alwaysPro) {
       return;
@@ -103,7 +104,10 @@ class InAppPurchases {
   }
 
   static Future<void> clearTransactionsIos() async {
-    if (Platform.isIOS) {
+    if (!Platform.isIOS) {
+      return;
+    }
+
     final transactions = await SKPaymentQueueWrapper().transactions();
     for (final transaction in transactions) {
       try {
@@ -125,6 +129,28 @@ class InAppPurchases {
       }
     }
   }
+
+  static void confirmPendingPurchases() async {
+    // On iOS this results in a "Sign in with Apple ID" dialog
+    if (!Platform.isAndroid) {
+      return;
+    }
+
+    InAppPurchaseConnection.enablePendingPurchases();
+    final iapCon = InAppPurchaseConnection.instance;
+
+    var pastPurchases = await iapCon.queryPastPurchases();
+    for (var pd in pastPurchases.pastPurchases) {
+      if (pd.pendingCompletePurchase) {
+        Log.i("Pending Complete Purchase - ${pd.productID}");
+
+        try {
+          await iapCon.completePurchase(pd);
+        } catch (e, stackTrace) {
+          logException(e, stackTrace);
+        }
+      }
+    }
   }
 }