[Fix] InputDecoration prefix & suffix

Runtime/material/input_decorator.cs

             this.hasFloatingPlaceholder = hasFloatingPlaceholder;
             this.isDense = isDense;
             this.contentPadding = contentPadding;
+            this.prefix = prefix;
+            this.prefixText = prefixText;
+            this.suffix = suffix;
+            this.suffixText = suffixText;
             this.suffixIcon = suffixIcon;
             this.suffixStyle = suffixStyle;
             this.counter = counter;