Ensure that update-token does not delete or alter existing subscriptions for UAID

[jrconlin]

Getting a report that one of the possible reasons for FxA Send Tab failures happening on android may be that

1. FxA reports a push publish error
2. Push on android deletes the native FCM token, and requests a new one.
3. The new FCM token is sent to the Push Component via PushManager(...).update(...)
4. UA eventually calls PushManager(...).verify_connection(...) which results in the server returning no subscriptions for the user.

We should ensure that UAID is not altered and the subscriptions are not dropped on a FCM token update. We may also need to file an additional bug against the Android Components Push Module if we think the problem might be in the hand-off.

[jonalmeida]

This issue seems to be closed, but it's unclear to me what the next steps are. It looks like there were some tests linked to it being closed.

[jrconlin]

Basically, it's adding proof that the server is not altering the route data whenever a new vendor token is sent. This ensures that the problem is not with the update path.

In essence, it's reducing the number of unknowns.

[jonalmeida]

That sounds fair. Should I file an issue in app services then as the next step to investigate? We're still seeing the issue for the Android consumers.

[jrconlin]

Yes. I'm hoping that fixing the metric tagging issue helps resolve some of this as well, but for now, it's still very much a mystery.