Chat: Set mock empty file size to 10KB

Author: Ruslan Farkhutdinov

apps/demos/Demos/Chat/FileAttachments/jQuery/data.js

@@ -23,7 +23,7 @@ const createEmptyAttachment = (name, type) => {
   return {
     name,
     url,
-    size: 0,
+    size: 1024 * 10,
   };
 };