use up svg icon

packages/stream_chat_flutter/lib/src/message_list_view.dart

@@ -710,12 +710,13 @@ class _MessageListViewState extends State<MessageListView> {
                       );
                     }
                   },
-                  child: Transform.rotate(
-                    angle: widget.reverse ? 0 : pi,
-                    child: StreamSvgIcon.down(
-                      color: _streamTheme.colorTheme.textHighEmphasis,
-                    ),
-                  ),
+                  child: widget.reverse
+                      ? StreamSvgIcon.down(
+                          color: _streamTheme.colorTheme.textHighEmphasis,
+                        )
+                      : StreamSvgIcon.up(
+                          color: _streamTheme.colorTheme.textHighEmphasis,
+                        ),
                 ),
                 if (showUnreadCount)
                   Positioned(

packages/stream_chat_flutter/lib/src/stream_svg_icon.dart

@@ -37,6 +37,18 @@ class StreamSvgIcon extends StatelessWidget {
         height: size,
       );
 
+  /// [StreamSvgIcon] type
+  factory StreamSvgIcon.up({
+    double? size,
+    Color? color,
+  }) =>
+      StreamSvgIcon(
+        assetName: 'Icon_up.svg',
+        color: color,
+        width: size,
+        height: size,
+      );
+
   /// [StreamSvgIcon] type
   factory StreamSvgIcon.attach({
     double? size,