refac: treat AdjustAppStorePurchase receipt as UnityIAP base64 encoded one

Author: uerceg

Assets/Adjust/Test/CommandExecutor.cs

@@ -993,10 +993,14 @@ private void VerifyPurchase()
             string productId = _command.GetFirstParameterValue("productId");
             string receipt = _command.GetFirstParameterValue("receipt");
 
+            // recreate UnityIAP base64 encoding of the receipt
+            var receiptBytes = System.Text.Encoding.UTF8.GetBytes(receipt);
+            string receiptBase64 = System.Convert.ToBase64String(receiptBytes);
+
             AdjustAppStorePurchase purchase = new AdjustAppStorePurchase(
                 transactionId,
                 productId,
-                receipt);
+                receiptBase64);
 
             Adjust.verifyAppStorePurchase(purchase, VerificationInfoCallback);
 #elif UNITY_ANDROID

Assets/Adjust/iOS/AdjustUnity.mm

@@ -863,7 +863,8 @@ void _AdjustVerifyAppStorePurchase(const char* transactionId,
 
         // Receipt.
         if (receipt != NULL) {
-            dataReceipt = [[NSString stringWithUTF8String:receipt] dataUsingEncoding:NSUTF8StringEncoding];
+            NSString *stringReceiptBase64 = [NSString stringWithUTF8String:receipt];
+            dataReceipt = [[NSData alloc] initWithBase64EncodedString:stringReceiptBase64 options:0];
         }
 
         // Scene name.