Fix Init_KeyBindings_Are_Not_Reset unit test failing

Author: BDisp

Terminal.Gui/App/Keyboard/KeyboardImpl.cs

@@ -69,8 +69,24 @@ public void Dispose ()
         Application.PrevTabKeyChanged -= OnPrevTabKeyChanged;
     }
 
+    private IApplication? _app;
+
     /// <inheritdoc/>
-    public IApplication? App { get; set; }
+    public IApplication? App
+    {
+        get => _app;
+        set
+        {
+            _app = value;
+
+            _quitKey = _app?.Keyboard.QuitKey ?? Key.Esc;
+            _arrangeKey = _app?.Keyboard.ArrangeKey ?? Key.F5.WithCtrl;
+            _nextTabGroupKey = _app?.Keyboard.NextTabGroupKey ?? Key.F6;
+            _nextTabKey = _app?.Keyboard.NextTabKey ?? Key.Tab;
+            _prevTabGroupKey = _app?.Keyboard.PrevTabGroupKey ?? Key.F6.WithShift;
+            _prevTabKey = _app?.Keyboard.PrevTabKey ?? Key.Tab.WithShift;
+        }
+    }
 
     /// <inheritdoc/>
     public KeyBindings KeyBindings { get; internal set; } = new (null);