Added auto hide functionality for header and footer

packages/hms_room_kit/lib/src/meeting/meeting_navigation_visibility_controller.dart

@@ -1,10 +1,36 @@
+///Dart imports
+import 'dart:async';
+
+///Package imports
 import 'package:flutter/widgets.dart';
 
 class MeetingNavigationVisibilityController extends ChangeNotifier {
   bool showControls = true;
 
+  ///This variable stores whether the timer is active or not
+  ///
+  ///This is done to avoid multiple timers running at the same time
+  bool _isTimerActive = false;
+
+  ///This method toggles the visibility of the buttons
   void toggleControlsVisibility() {
     showControls = !showControls;
+
+    ///If the controls are now visible and
+    ///If the timer is not active, we start the timer
+    if (showControls && !_isTimerActive) {
+      startTimerToHideButtons();
+    }
     notifyListeners();
   }
+
+  ///This method starts a timer for 5 seconds and then hides the buttons
+  void startTimerToHideButtons() {
+    _isTimerActive = true;
+    Timer(const Duration(seconds: 5), () {
+      showControls = false;
+      _isTimerActive = false;
+      notifyListeners();
+    });
+  }
 }