Fix Origina Payload parser

* Fixed the original payload parser so that it will parse 'actionSelected' (button press) if the _additionalData dictionary was already initialized

Author: Nightsd01

iOS_SDK/OneSignalSDK/Source/OSNotificationPayload.m

@@ -72,6 +72,10 @@ -(void)parseOriginalPayload {
     //and 'actionSelected' was not being set in additionalData
     if (_rawPayload[@"actionSelected"] && !_additionalData) {
         _additionalData = @{@"actionSelected" : _rawPayload[@"actionSelected"]};
+    } else if (_rawPayload[@"actionSelected"]) {
+        NSMutableDictionary *additional = [_additionalData mutableCopy];
+        additional[@"actionSelected"] = _rawPayload[@"actionSelected"];
+        _additionalData = additional;
     }
 }