[ButtonGroup] Fixed connected button groups to not morph button size.

Resolves #4782

PiperOrigin-RevId: 771105111
(cherry picked from commit 0e6d4f4)

Author: pekingme

lib/java/com/google/android/material/button/res/values/styles.xml

@@ -27,6 +27,7 @@
   <style name="Widget.Material3.MaterialButtonGroup.Connected">
     <item name="android:spacing">@dimen/m3_comp_button_group_connected_small_between_space</item>
     <item name="innerCornerSize">8dp</item>
+    <item name="buttonSizeChange">@null</item>
     <item name="shapeAppearance">@style/ShapeAppearance.M3.Comp.ButtonGroup.Connected.Small.Container.Shape</item>
   </style>
 
@@ -42,7 +43,6 @@
     <item name="android:paddingTop">10dp</item>
     <item name="android:paddingBottom">10dp</item>
     <item name="innerCornerSize">@xml/m3_split_button_inner_corner_size_state_list</item>
-    <item name="buttonSizeChange">@null</item>
     <item name="shapeAppearance">@style/ShapeAppearance.M3.Sys.Shape.Corner.Full</item>
   </style>