remove useTheme from the doc

packages/react-native-sdk/docusaurus/docs/reactnative/05-ui-cookbook/20-call-duration.mdx

@@ -18,7 +18,6 @@ Here's how to implement a call duration display component:
 import React, { useEffect, useState } from 'react';
 import { View, Text, StyleSheet } from 'react-native';
 import { useCallStateHooks } from '@stream-io/video-react-bindings';
-import { useTheme } from '@stream-io/video-react-native-sdk';
 import { CallDuration } from './icons/CallDuration';
 
 const formatTime = (seconds: number) => {
@@ -32,7 +31,6 @@ const formatTime = (seconds: number) => {
 };
 
 const CallDurationBadge = () => {
-  const { theme } = useTheme();
   const [elapsed, setElapsed] = useState<string>('00:00');
   const { useCallSession } = useCallStateHooks();
   const session = useCallSession();
@@ -86,9 +84,8 @@ The CallDurationBadge component provides:
 You can customize the appearance of the CallDurationBadge by:
 
 1. Modifying the styles object
-2. Using different theme colors through the useTheme hook
-3. Adjusting the icon size or using a custom icon
-4. Changing the time format display
+2. Adjusting the icon size or using a custom icon
+3. Changing the time format display
 
 :::note
 For simplicity, the StyleSheet is not included in this guide.