[Gallery] Fix divider for bottom sheet demo on web (#300)

* Fix divider for bottom sheet demo on web

* Update code_segments.dart

gallery/gallery/lib/codeviewer/code_segments.dart

@@ -2696,7 +2696,12 @@ class CodeSegments {
       TextSpan(style: codeStyle.punctuationStyle, text: '),'),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
       TextSpan(style: codeStyle.classStyle, text: 'Divider'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '(),'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'thickness'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.numberStyle, text: '1'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
       TextSpan(style: codeStyle.classStyle, text: 'Expanded'),
       TextSpan(style: codeStyle.punctuationStyle, text: '('),
@@ -2984,7 +2989,12 @@ class CodeSegments {
       TextSpan(style: codeStyle.punctuationStyle, text: '),'),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
       TextSpan(style: codeStyle.classStyle, text: 'Divider'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '(),'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '('),
+      TextSpan(style: codeStyle.baseStyle, text: 'thickness'),
+      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
+      TextSpan(style: codeStyle.baseStyle, text: ' '),
+      TextSpan(style: codeStyle.numberStyle, text: '1'),
+      TextSpan(style: codeStyle.punctuationStyle, text: '),'),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a          '),
       TextSpan(style: codeStyle.classStyle, text: 'Expanded'),
       TextSpan(style: codeStyle.punctuationStyle, text: '('),

gallery/gallery/lib/demos/material/bottom_sheet_demo.dart

@@ -89,7 +89,7 @@ class _BottomSheetContent extends StatelessWidget {
               ),
             ),
           ),
-          Divider(),
+          Divider(thickness: 1),
           Expanded(
             child: ListView.builder(
               itemCount: 21,