fix: remove keyboard when tap outside text field (#4235)

frontend/appflowy_flutter/lib/mobile/presentation/database/board/widgets/group_card_header.dart

@@ -85,6 +85,11 @@ class _GroupCardHeaderState extends State<GroupCardHeader> {
                 ),
             maxLines: 1,
             style: titleTextStyle,
+            onTapOutside: (_) => context.read<BoardBloc>().add(
+                  // group header switch from TextField to Text
+                  // group name won't be changed
+                  BoardEvent.endEditingHeader(widget.groupData.id, null),
+                ),
           );
         }