Checklists: Checkboxes aren't formatted in markdown preview

### Expected

I expect checkboxes to appear as checkboxes in the markdown preview of a note.

### Observed

Checkboxes look fine in the editor, but in the markdown preview they look like this:

```
• [ ] one
• [ ] two
• [ ] three
```

### Reproduced

1. Create a new markdown note.
2. Add checklist items to the note.
3. Switch to the note preview.

In the editor:

In the preview:

Make|Model|Android Version|App Version
-|-|-|-
Motorola|moto e5 play|8.1.0|2.2
Redmi|Note 7|9|2.2

Original report from a public beta tester and I reproduced the issue.

Reproduce the issue by creating a markdown note with checklist items and switching to the note preview. Trace the markdown preview rendering path and compare it with the editor output. Done means checklist items render as checkboxes in the preview instead of bullet characters and unchecked markers.

Written by the indexing model from the issue text.