fix: revert back the appEnv and change the comment

packages/deriv_auth_ui/lib/src/features/setting_page/layouts/deriv_setting_layout.dart

@@ -20,6 +20,8 @@ class DerivSettingLayout extends StatefulWidget {
     this.appId = defaultAppId,
     this.devApp = 'com.deriv.app.dev',
     this.stagingApp = 'com.deriv.app.staging',
+    this.getAppEnv,
+    this.setAppEnv,
     Key? key,
   }) : super(key: key);
 
@@ -44,6 +46,12 @@ class DerivSettingLayout extends StatefulWidget {
   /// Staging flavor app.
   final String stagingApp;
 
+  /// Gets environment variable
+  final Future<bool>? getAppEnv;
+
+  /// Sets environment variable
+  final Future<void> Function({required bool value})? setAppEnv;
+
   @override
   _SettingsPageState createState() => _SettingsPageState();
 }
@@ -109,12 +117,29 @@ class _SettingsPageState extends State<DerivSettingLayout> {
         if (snapshot.hasData &&
             (snapshot.data?.packageName == widget.devApp ||
                 snapshot.data?.packageName == widget.stagingApp)) {
-          return const Padding(
-            padding: EdgeInsets.symmetric(horizontal: ThemeProvider.margin16),
+          return Padding(
+            padding:
+                const EdgeInsets.symmetric(horizontal: ThemeProvider.margin16),
             child: Row(
               children: <Widget>[
-                Text('Production environment'),
-                SizedBox(width: ThemeProvider.margin08),
+                const Text('Production environment'),
+                const SizedBox(width: ThemeProvider.margin08),
+                FutureBuilder<bool>(
+                    future: widget.getAppEnv,
+                    builder:
+                        (BuildContext context, AsyncSnapshot<bool?> snapshot) {
+                      if (snapshot.hasData && widget.setAppEnv != null) {
+                        return Switch(
+                          value: snapshot.data ?? false,
+                          onChanged: (bool val) {
+                            setState(() {
+                              widget.setAppEnv!(value: val);
+                            });
+                          },
+                        );
+                      }
+                      return const SizedBox.shrink();
+                    })
               ],
             ),
           );