Update HttpUtility.JavaScriptStringEncode method documentation to match with the implementation (#9901)

dotnet/runtime#100248

Author: GMPrakhar

xml/System.Web/HttpUtility.xml

@@ -653,7 +653,7 @@
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- This method encodes strings. For instance, single quotation marks and double quotation marks are included as `\'` and `\"` in the encoded string.
+ This method encodes strings. For instance, single quotation marks and double quotation marks are included as `\u0027` and `\"` in the encoded string.
 
  ]]></format>
         </remarks>