Update src/fragments/lib/push-notifications/react-native/migrate_from_previous_version/migrate-from-previous-version.mdx

Co-authored-by: Jim Blanchard <[email protected]>

Author: cshfang

src/fragments/lib/push-notifications/react-native/migrate_from_previous_version/migrate-from-previous-version.mdx

@@ -141,7 +141,7 @@ dependencies {
 
 ### Add required polyfills
 
-You need to add the crypto.getRandomValues and URL polyfill to your application's entry point file (in most React Native apps this will be the top level `index.js`).
+You need to add the crypto.getRandomValues and URL polyfills to your application's entry point file (in most React Native apps this will be the top level `index.js`).
 
 ```js
 // Example index.js