Revert "Fix Backbutton is not displayed when there is a endDrawer (#101869)" (#101998)

This reverts commit e2d12060a2bc574a3e1209e206d5cf031cdbc335.

packages/flutter/lib/src/material/app_bar.dart

@@ -807,9 +807,9 @@ class _AppBarState extends State<AppBar> {
 
     final bool hasDrawer = scaffold?.hasDrawer ?? false;
     final bool hasEndDrawer = scaffold?.hasEndDrawer ?? false;
+    final bool canPop = parentRoute?.canPop ?? false;
     final bool useCloseButton = parentRoute is PageRoute<dynamic> && parentRoute.fullscreenDialog;
-    final bool requiresAppBarDismiss = scaffold?.requiresAppBarDismiss ?? false;
+
-    final bool hasActiveRouteBelow = parentRoute?.hasActiveRouteBelow ?? false;
     final double toolbarHeight = widget.toolbarHeight ?? appBarTheme.toolbarHeight ?? kToolbarHeight;
     final bool backwardsCompatibility = widget.backwardsCompatibility ?? appBarTheme.backwardsCompatibility ?? false;
 
@@ -880,7 +880,7 @@ class _AppBarState extends State<AppBar> {
           tooltip: MaterialLocalizations.of(context).openAppDrawerTooltip,
         );
       } else {
-        if (hasActiveRouteBelow || requiresAppBarDismiss)
+        if (!hasEndDrawer && canPop)
           leading = useCloseButton ? const CloseButton() : const BackButton();
       }
     }

packages/flutter/lib/src/material/scaffold.dart

@@ -1917,20 +1917,13 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
 
   /// Whether this scaffold has a non-null [Scaffold.appBar].
   bool get hasAppBar => widget.appBar != null;
-
   /// Whether this scaffold has a non-null [Scaffold.drawer].
   bool get hasDrawer => widget.drawer != null;
-
   /// Whether this scaffold has a non-null [Scaffold.endDrawer].
   bool get hasEndDrawer => widget.endDrawer != null;
-
   /// Whether this scaffold has a non-null [Scaffold.floatingActionButton].
   bool get hasFloatingActionButton => widget.floatingActionButton != null;
 
-  /// Whether this scaffold requires [Scaffold.appBar] to automatically add
-  /// dismiss button.
-  bool get requiresAppBarDismiss => _persistentSheetHistoryEntry != null;
-
   double? _appBarMaxHeight;
   /// The max height the [Scaffold.appBar] uses.
   ///
@@ -2058,28 +2051,28 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin, Resto
   PersistentBottomSheetController<dynamic>? _currentBottomSheet;
   final GlobalKey _currentBottomSheetKey = GlobalKey();
 
-  LocalHistoryEntry? _persistentSheetHistoryEntry;
   void _maybeBuildPersistentBottomSheet() {
     if (widget.bottomSheet != null && _currentBottomSheet == null) {
       // The new _currentBottomSheet is not a local history entry so a "back" button
       // will not be added to the Scaffold's appbar and the bottom sheet will not
       // support drag or swipe to dismiss.
       final AnimationController animationController = BottomSheet.createAnimationController(this)..value = 1.0;
+      LocalHistoryEntry? persistentSheetHistoryEntry;
       bool _persistentBottomSheetExtentChanged(DraggableScrollableNotification notification) {
         if (notification.extent > notification.initialExtent) {
-          if (_persistentSheetHistoryEntry == null) {
+          if (persistentSheetHistoryEntry == null) {
-            _persistentSheetHistoryEntry = LocalHistoryEntry(onRemove: () {
+            persistentSheetHistoryEntry = LocalHistoryEntry(onRemove: () {
               if (notification.extent > notification.initialExtent) {
                 DraggableScrollableActuator.reset(notification.context);
               }
               showBodyScrim(false, 0.0);
               _floatingActionButtonVisibilityValue = 1.0;
-              _persistentSheetHistoryEntry = null;
+              persistentSheetHistoryEntry = null;
             });
-            ModalRoute.of(context)!.addLocalHistoryEntry(_persistentSheetHistoryEntry!);
+            ModalRoute.of(context)!.addLocalHistoryEntry(persistentSheetHistoryEntry!);
           }
-        } else if (_persistentSheetHistoryEntry != null) {
+        } else if (persistentSheetHistoryEntry != null) {
-          ModalRoute.of(context)!.removeLocalHistoryEntry(_persistentSheetHistoryEntry!);
+          ModalRoute.of(context)!.removeLocalHistoryEntry(persistentSheetHistoryEntry!);
         }
         return false;
       }

packages/flutter/lib/src/widgets/navigator.dart

@@ -486,6 +486,7 @@ abstract class Route<T> {
   }
 
   /// Whether there is at least one active route underneath this route.
+  @protected
   bool get hasActiveRouteBelow {
     if (_navigator == null)
       return false;