title: Strategy for handling dark mode on <10 android devices
body: <p>So I have implemented dark mode in my app and its working well, following the system wide setting on Android 10 and 11 devices.</p>
  <p>Is there a way to allow users of pre Android 10 devices to select light or dark theme? My MinSDK is 21</p>
  <p>Thinking of a switch in the settings if possible to allow selection and then I use:</p>
  <p><code>AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)</code></p>
  <p>(is this correct?)</p>
  <p>I also guess I should hide this switch on Android 10 onwards devices and let the system deal with light dark mode?  Is there a best practice I should follow for this sort of thing? Is my proposed way of working correct?</p>
  <p>Thanks</p>