Adjusts halo ellipse size

Changes halo ellipse dimensions from 25x25 to 22x22. I think this size is a bit closer to what the spec shows.

Author: Keboo

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ToggleButton.xaml

@@ -440,8 +440,8 @@
                   </Ellipse.RenderTransform>
                 </Ellipse>
                 <Ellipse x:Name="halo"
-                         Width="25"
-                         Height="25"
+                         Width="22"
+                         Height="22"
                          Margin="0"
                          HorizontalAlignment="Center"
                          VerticalAlignment="Center"