minor fixes

Samples/UIWidgetsSamples_2019_4/Assets/Editor/EditorWindowSample/GalleryMain.cs

-#if UNITY_EDITOR
 using System.Collections.Generic;
 using UIWidgetsGallery.gallery;
 using Unity.UIWidgets.Editor;
             ui_.runApp(new GalleryApp());
         }
     }
-}
-#endif
+}

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

 #if !UNITY_EDITOR && UNITY_ANDROID
             if (!IsAndroidInitialized()) {return ;}
 #endif
-            
-            base.OnEnable();
-#if UNITY_IOS
+#if !UNITY_EDITOR && UNITY_IOS
+            
+            base.OnEnable();
             D.assert(_wrapper == null);
             _configurations = new Configurations();
             _wrapper = new UIWidgetsPanelWrapper();

engine/Build.bee.cs

     private static string flutterRoot;
 
     //this setting is disabled by default, don't change it unless you know what you are doing
-    //it must be set the same as the settings we choose to build skia and flutter engine
+    //it must be set the same as the settings we choose to build the flutter txt library
     //refer to the readme file for the details
     private static bool ios_bitcode_enabled = false;