Google Hangouts onNotificationPosted firing on swipe notification removal

[xhuytox]

Because the event is fired on swipe notification removal, this causes a duplicate notification to be sent when the user goes to swipe away a notification on the phone. This seems to be isolated to Google Hangouts notifications as Gmail and Messenger (Google) did not do this. Not sure if it's a big enough deal to fix, but opening up the issue anyways. On debug, I did noticed that the notification that comes from the removal swipe has a notification.flag = 16 instead of the usual 17 that comes from when a Hangout notification appears.

[xhuytox]

Similar to #10, after restarting my phone, this issue doesn't happen anymore. Closing for now.

[ThomasGaubert]

Good to know! I'll keep an eye our for it (and the other issue) and possibly add logging to catch something like this in the future.