Fixes #1161

Author: batzen

Fluent.Ribbon/Themes/Controls/BackstageTabControl.xaml

@@ -204,6 +204,7 @@
                             Padding="22 7 0 7"
                             VerticalAlignment="Top"
                             AutomationProperties.Name="{Binding Uid, RelativeSource={RelativeSource Self}}"
+                            AutomationProperties.AcceleratorKey="ESC"
                             Command="{x:Static Fluent:RibbonCommands.OpenBackstage}"
                             Visibility="{Binding Path=IsBackButtonVisible, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource Fluent.Ribbon.Converters.BoolToVisibilityConverter}}">
                         <Button.Margin>