[Feature] The default icon at the end of DropDownButton can be modified

[Hooooot]

Is your feature request related to a problem? Please describe

I hope that the icon in DropDownButton.xaml can be customized by the user to display and indicate the direction of the arrow.

The following is the definition code of the icons in the project in DropDownButton.xaml

<Grid Grid.Column="2" Margin="{StaticResource ButtonChevronIconMargin}">
    <controls:SymbolIcon FontSize="10" Symbol="ChevronDown24" />
</Grid>

Describe the solution you'd like

An enumeration variable to indicate arrow direction and whether to display arrows.

Describe alternatives you've considered

No response

Additional context

No response