Use better way to handle gallery with no images and page with no images

.devcontainer/Dockerfile

@@ -7,4 +7,4 @@ RUN apt-get clean
 
 RUN git clone https://github.com/flutter/flutter.git -b stable --depth 1 /flutter
 ENV PATH="/flutter/bin:$PATH"
-RUN flutter doctor
+RUN flutter doctor && dart --disable-analytics && flutter --disable-analytics

.devcontainer/devcontainer.json

@@ -8,7 +8,8 @@
     "vscode": {
       "extensions": [
         "Dart-Code.dart-code",
-        "Dart-Code.flutter"
+        "Dart-Code.flutter",
+        "Google.arb-editor"
       ]
     }
   }