Merge pull request #352 from GetStream/fix/file-picker-image-as-file

fix(UI-Kit): Show selected attachment file as file in message input

packages/stream_chat_flutter/lib/src/message_input.dart

@@ -656,6 +656,7 @@ class MessageInputState extends State<MessageInput> {
   Timer _debounce;
 
   String _previousValue;
+
   void _onChanged(BuildContext context, String s) {
     if (s == _previousValue) {
       return;
@@ -1962,12 +1963,6 @@ class MessageInputState extends State<MessageInput> {
 
     final extraDataMap = <String, dynamic>{};
 
-    if (mimeType?.type == 'video' || mimeType?.type == 'image') {
-      attachmentType = mimeType.type;
-    } else {
-      attachmentType = 'file';
-    }
-
     if (mimeType?.subtype != null) {
       extraDataMap['mime_type'] = mimeType.subtype.toLowerCase();
     }