Adds mui expandMore icon and switches them

src/app/components/Sidebar/index.tsx

@@ -1,6 +1,7 @@
 import AppContext from "@/appContext";
 import { Button } from "@material-tailwind/react";
 import CircularProgress from '@mui/material/CircularProgress';
+import ExpandMoreIcon from '@mui/icons-material/ExpandMore';
 import MenuItem from '@mui/material/MenuItem';
 import Select, { SelectChangeEvent } from '@mui/material/Select';
 import React, { useContext, useState } from "react";
@@ -123,7 +124,7 @@ export const Sidebar: React.FC = () => {
       <div className="flex flex-column w-full" style={{ ...styles.textHeaderWrapper, flexDirection: "column", }}>
         <div className="mb-6 w-full">
           <h4 style={styles.h4}>Select demo url to index</h4>
-          <Select className="w-full" value={url} data-testid="url-selector" onChange={handleUrlChange} MenuProps={{
+          <Select className="w-full" value={url} data-testid="url-selector" onChange={handleUrlChange} IconComponent={ExpandMoreIcon} MenuProps={{
             keepMounted: true,
             PaperProps: {
               style: {
@@ -144,7 +145,7 @@ export const Sidebar: React.FC = () => {
               infoText="The chunking method determines how documents are split into smaller chunks for vector embedding to accommodate size limits. Overlapping content between chunks preserves context, improving search relevance."
             />
           </h4>
-          <Select value={splittingMethod} className="w-full" onChange={handleSplittingMethodChange}
+          <Select IconComponent={ExpandMoreIcon} value={splittingMethod} className="w-full" onChange={handleSplittingMethodChange}
             renderValue={(value) => {
               if (value === "markdown") {
                 return "Markdown Chunking";