Add INTERNET permission for Android

This was annoying.
I couldn't figure out why my release build wouldn't show the videos
properly but the debug build worked just fine.
After searching through many GitHub issues I finally decided to search
the actual error shown in the app.
Searching for "android webview net err_cache_miss" on DuckDuckGo,
I found the answer on Stack Overflow at
https://stackoverflow.com/a/31533625

android/app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
          In most cases you can leave this as-is, but you if you want to provide
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
+    <uses-permission android:name="android.permission.INTERNET"/>
     <application
         android:name="io.flutter.app.FlutterApplication"
         android:label="IZ*ONE"