docs(messaging): add header for android permissions section (#6917)

Author: Bilal-Abdeen

docs/messaging/usage/index.md

@@ -68,6 +68,8 @@ async function requestUserPermission() {
 The permissions API for iOS provides much more fine-grain control over permissions and how they're handled within your
 application. To learn more, view the advanced [iOS Permissions](/messaging/ios-permissions) documentation.
 
+## Android - Requesting permissions
+
 On Android API level 32 and below, you do not need to request user permission. This method can still be called on Android devices; however, and will always resolve successfully. For API level 33+ you will need to request the permission manually using either the built-in react-native `PermissionsAndroid` APIs or a related module such as `react-native-permissions`
 
 ```