* Use `curly_braces_in_flow_control_structures` for `material`

* include test/material

* add back removed comments

This reverts commit c82ddd39.

This reverts commit 5fd259be.

* Adding onLongPress for DataRow

Useful to be able to e.g. start a selection mode of rows or show a drop down menu.

* Test for onLongPress

* Changed parameter

* Reland "Android Q transition by default (#82670)"

This reverts commit 4053b4b1.

* Fix `overall_experience_test.dart` for flutter_tools

This reverts commit a1ae4fea.

This change prevents DataRow from being enabled when onSelectChanged is null.

[Material] Parent checkbox in DataTable should deselect all, if children checkboxes are disabled or selected  (#67938)

* Add tristate to parent checkbox for DataTable to follow Material specifications

* Add decoration parameter to DataTable and DataTableTheme

Migrate Material framework tests to null safety.

This reverts commit cb4b8677.

* Fix sort indicator for DataTables

As per material spec ascending order should be shown via an upward arrow
This commit changes the displayed arrows accordingly.

* Test sort indicator orientation in DataTable

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

* Change onSort and add tests

* Add doc

* Regression test

* Remove if (true)

* Make test clearer

* Clearer comment