docs(react-native): fix example to include initial state (#10172)

* docs: fix expo-network example code block

* Apply suggestions from code review

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: 3 people

docs/framework/react/react-native.md

@@ -41,9 +41,23 @@ import { onlineManager } from '@tanstack/react-query'
 import * as Network from 'expo-network'
 
 onlineManager.setEventListener((setOnline) => {
+  let initialised = false
+
   const eventSubscription = Network.addNetworkStateListener((state) => {
+    initialised = true
     setOnline(!!state.isConnected)
   })
+
+  Network.getNetworkStateAsync()
+    .then((state) => {
+      if (!initialised) {
+        setOnline(!!state.isConnected)
+      }
+    })
+    .catch(() => {
+      // getNetworkStateAsync can reject on some platforms/SDK versions
+    })
+
   return eventSubscription.remove
 })
 ```