[BUG]: Initial sync with empty AnkiWeb account asks which collection to keep

### Checked for duplicates?

- [X] This issue is not a duplicate

### What are the steps to reproduce this bug?

1. Load a deck into AnkiDroid and study
1. Create a new AnkiWeb account. It has no collections
3. Sync in AnkiDroid. Add email/password

### Expected behaviour

Since the AnkiWeb account is completely empty, AnkiDroid should simply sync to it.

### Actual behaviour

AnkiDroid says:

Select collection to keep

> The collections can't be combined
> Which collection do you want to keep
> Cancel AnkiWeb AnkiDroid

Isn't AnkiDroid able to work out that AnkiWeb is completely empty and sync without asking for this prompt?

### Debug info

```text
2.16.2
```

### (Optional) Anything else you want to share?

.

### Research

- [X] I am reporting a bug specific to AnkiDroid (Android app)
- [X] I have checked the [manual](https://ankidroid.org/docs/manual.html) and the [FAQ](https://github.com/ankidroid/Anki-Android/wiki/FAQ) and could not find a solution to my issue
- [ ] (Optional) I have confirmed the issue is not resolved in the latest alpha release ([instructions](https://docs.ankidroid.org/manual.html#betaTesting))