fix

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/GalleryMain.cs

 
         protected override void onEnable()
         {
-            AndroidPlatformUtil.ShowStatusBar(true);
             AddFont("Material Icons", new List<string> {"MaterialIcons-Regular.ttf"}, new List<int> {0});
             AddFont("CupertinoIcons", new List<string> {"CupertinoIcons.ttf"}, new List<int> {0});
             AddFont("GalleryIcons", new List<string> {"gallery/GalleryIcons.ttf"}, new List<int> {0});

com.unity.uiwidgets/Runtime/engine2/AndroidPlatformUtil.cs

 
 namespace Unity.UIWidgets.engine2 {
     public static class AndroidPlatformUtil {
+        public static class UIWidgetsAndroidConfiguration{
+            public const bool showStatusBar = true;
+        }
+
         [DllImport(NativeBindings.dllName)]
         internal static extern void InitUnpackFile(UnpackFileCallback unpack);
 
         public static void Init() {
             InitUnpackFile(unpackFile);
             GL.IssuePluginEvent(GetUnityContextEventFunc(), 1);
+            if( UIWidgetsAndroidConfiguration.showStatusBar){
+                ShowStatusBar(true);
+            }
-#if !UNITY_EDITOR
-#endif
         }
     }
 }

com.unity.uiwidgets/Runtime/engine2/UIWidgetsPanel.cs

 
         void _handleViewMetricsChanged(string method, List<JSONNode> args) {
             _wrapper.displayMetrics.onViewMetricsChanged();
+            Window.instance.updateSafeArea();
             Window.instance.onMetricsChanged?.Invoke();
         }
         

com.unity.uiwidgets/Runtime/rendering/binding.cs

             D.assert(renderView != null);
             addPersistentFrameCallback(_handlePersistentFrameCallback);
             initMouseTracker();
+            window.updateSafeArea();
         }
         
         public void initRenderView() {
         }
 
         void _handlePersistentFrameCallback(TimeSpan timeStamp) {
-            window.updateSafeArea();
             drawFrame();
             _mouseTracker.schedulePostFrameCheck();
         }