Fix Android issues

lib/pages/entry/entry_detail_page.dart

@@ -175,6 +175,20 @@ class EntryDetailPage extends GetView<EntryController> {
   }
 
   Widget _buildCategoryDropdown() {
+    final eligibleCategories = controller.getFilteredCategories();
+
+    return DropdownButtonFormField<NewCategory>(
+      decoration: InputDecoration(labelText: 'カテゴリ'),
+      value: controller.selectedCategory.value,
+      items: eligibleCategories.map((category) => DropdownMenuItem<NewCategory>(
+        value: category,
+        child: Text(category.categoryName),
+      )).toList(),
+      onChanged: (value) => controller.updateCategory(value),
+    );
+  }
+
+  Widget _buildCategoryDropdown_old() {
     final eligibleCategories = controller.categories.where((c) =>
     c.baseCategory == controller.selectedCategory.value?.baseCategory
     ).toList();