update message input radius

lib/src/media_list_view.dart

@@ -63,10 +63,11 @@ class _MediaListViewState extends State<MediaListView> {
                           right: 8,
                         ),
                         child: CircleAvatar(
-                          maxRadius: 12.0,
+                          radius: 12,
                           backgroundColor: Colors.white,
                           child: Icon(
                             StreamIcons.check,
+                            size: 24,
                             color: Colors.black,
                           ),
                         ),

lib/src/message_input.dart

@@ -1170,8 +1170,8 @@ class MessageInputState extends State<MessageInput> {
 
   Positioned _buildRemoveButton(_SendingAttachment attachment) {
     return Positioned(
-      height: 16,
-      width: 16,
+      height: 24,
+      width: 24,
       top: 4,
       right: 4,
       child: RawMaterialButton(
@@ -1192,7 +1192,7 @@ class MessageInputState extends State<MessageInput> {
         child: Center(
           child: Icon(
             StreamIcons.close,
-            size: 15,
+            size: 24,
             color: Colors.white,
           ),
         ),