List of error codes?

## What feature would you like to see?

I'm trying to better handle Firebase auth errors, and I can't find list of all possible error codes. I've managed to find [this](https://github.com/firebase/FirebaseUI-Android/blob/4455f411e3605743bb4511d1a75cda7f398bc399/auth/src/main/java/com/firebase/ui/auth/util/FirebaseAuthError.java), but it's not a complete list.

## How would you use it?

```
val e: FirebaseAuthException
if (e.errorCode == ErrorCodes.ERROR_INVALID_CERT_HASH {
reportToFirebase("Something is horribly wrong with oauth")
}
```