[UWP] Adjust AutoSuggestBox's TextBoxStyle style name to prevent possible crash

[pauldipietro]

Description of Change

Presently trying to set the AutoSuggestBox style like the following for UWP causes a crash:

<Style TargetType="AutoSuggestBox">
    <Setter Property="FontFamily" Value="Comic Sans MS"/>
</Style>

Although setting this property in a native UWP app would not work (the style should be applied as a value on TextBoxStyle), it wouldn't crash. The crash here appears due to a naming conflict on the AutoSuggestBoxTextBoxStyle key being used; renaming this appears to prevent this crash from occurring. The App.xaml in the UWP gallery project was not modified for this PR to keep global styles the same, but would reproduce the issue if added.

Bugs Fixed

https://bugzilla.xamarin.com/show_bug.cgi?id=41919

API Changes

None

Behavioral Changes

None

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of master at time of PR
• Changes adhere to coding standard
• Consolidate commits as makes sense