ListView WinUI Group Header renderers incorrect string for first group header

### Description

Go to the ListRefreshView sample in the gallery on WinUI

### Steps to Reproduce

Go to the ListRefreshView sample in the gallery on WinUI

### Version with bug

Preview 13

### Last version that worked well

Unknown/Other

### Affected platforms

Windows

### Affected platform versions

WinUI

### Did you find any workaround?

_No response_

### Relevant log output

_No response_