Make editor make sense

osu.Game/Screens/Edit/Editor.cs

@@ -80,8 +80,6 @@ public partial class Editor : ScreenWithBeatmapBackground, IKeyBindingHandler<Gl
 
         public override float BackgroundParallaxAmount => 0.1f;
 
-        public override bool AllowUserExit => false;
-
         public override bool HideOverlaysOnEnter => true;
 
         public override bool DisallowExternalBeatmapRulesetChanges => true;
@@ -194,6 +192,8 @@ protected override UserActivity InitialActivity
             }
         }
 
+        protected override bool InitialBackButtonVisibility => false;
+
         protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
             => dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
 
@@ -760,11 +760,6 @@ public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
 
             switch (e.Action)
             {
-                case GlobalAction.Back:
-                    // as we don't want to display the back button, manual handling of exit action is required.
-                    this.Exit();
-                    return true;
-
                 case GlobalAction.EditorCloneSelection:
                     Clone();
                     return true;