Merge branch 'MTRNord/external' into 'main'

Allow app to be moved to external storage

See merge request famedly/fluffychat!778

android/app/src/main/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           xmlns:tools="http://schemas.android.com/tools"
-    package="chat.fluffy.fluffychat">
+    package="chat.fluffy.fluffychat" android:installLocation="auto">
     <!-- io.flutter.app.FlutterApplication is an android.app.Application that
          calls FlutterMain.startInitialization(this); in its onCreate method.
          In most cases you can leave this as-is, but you if you want to provide