Fix VisualState that was crashing, had a reference to unused element

Author: michael-hawker

Microsoft.Toolkit.Uwp.UI.Controls.Core/TabbedCommandBar/TabbedCommandBar.xaml

@@ -30,6 +30,14 @@
                             <RowDefinition Height="*" />
                         </Grid.RowDefinitions>
                         <VisualStateManager.VisualStateGroups>
+                            <VisualStateGroup x:Name="AutoSuggestGroup">
+                                <VisualState x:Name="AutoSuggestBoxVisible" />
+                                <VisualState x:Name="AutoSuggestBoxCollapsed">
+                                    <VisualState.Setters>
+                                        <Setter Target="TopPaneAutoSuggestArea.Visibility" Value="Collapsed" />
+                                    </VisualState.Setters>
+                                </VisualState>
+                            </VisualStateGroup>
                             <VisualStateGroup x:Name="BackButtonGroup">
                                 <VisualState x:Name="BackButtonVisible" />
                                 <VisualState x:Name="BackButtonCollapsed">