title: Flutter activity background goes black when coming back from background
body: <p>I'm using a Flutter Android app and an 3rd party library which launches an activity on top of the app once triggered.</p>
  <p>The 3rd party library's activity is set as translucent, and in fact once launching this activity at first, it does show as translucent.
  The problem is when turning off the screen and then back on, or sending the app to the background and then to the foreground. The background goes BLACK!</p>
  <p>*let me state that when changing orientation, the activity is displayed as it should.</p>
  <p>This does not happen in native apps, only in Flutter.</p>
  <p>I've tried overriding <code>getBackgroundMode</code> in the <code>flutterActivity</code>, which works on some APIs (26 and above) and on some apps, but not all.</p>
  <p>Any ideas what else I can try?</p>