Fix a few notices

lib/ui/routes/settings/account_privacy_settings.dart

@@ -180,9 +180,7 @@ class DataConservationPolicyTile extends SettingsTile {
     required this.title,
     required this.onChange,
     required this.minValue,
-  })  : assert(title != null),
-        assert(onChange != null),
-        assert(minValue != null);
+  });
 
   @override
   Widget build(BuildContext context) {

lib/ui/routes/settings/account_security_settings.dart

@@ -140,8 +140,7 @@ class _SecurityQuestionsDialog extends StatefulWidget {
   final SecuritySettings settings;
 
   const _SecurityQuestionsDialog({Key? key, required this.settings})
-      : assert(settings != null),
-        super(key: key);
+      : super(key: key);
 
   @override
   __SecurityQuestionsDialogState createState() =>

lib/ui/routes/settings/account_settings_route.dart

@@ -31,10 +31,7 @@ class _SettingsSection {
     required this.subtitle,
     required this.icon,
     required this.onBuild,
-  })  : assert(title != null),
-        assert(subtitle != null),
-        assert(icon != null),
-        assert(onBuild != null);
+  });
 }
 
 class AccountSettingsRoute extends StatelessWidget {