(consideration) Remove PII from user key

[brooswit]

Using an email as the user's key sets a poor example.

• PII should not be used as a user's key.
• A user's key should be something that doesn't change, and a user's email could change.

[eli-darkly]

I would be inclined to simplify this even further. In most or all of the other hello apps, we're using this smaller set of properties:

{ "key": "example-user-key", "name": "Sandy" }

The point of the hello app isn't to demonstrate how to set user properties, especially not unusual usages like an array of values in a custom attribute— those are covered by other kinds of docs. And I think there's value in using the exact same values in each hello app, in case someone is comparing usage across languages to better understand the per-SDK differences. I think probably we just forgot to do this one.

[eli-darkly]

@ember-stevens The change that I was suggesting wasn't just to change the key value, but also to remove all the other properties and add the name that was in my example. Then it would match the other hello projects. I don't think there's any value in having firstName, lastName, email, and custom here.

[eli-darkly]

There's an extra closing brace here that still needs to be removed.