gtk4: get fancy blue "suggested-action" button for Print in print dialog

Change-Id: I60edccc6bb1a5cbbb615ad7be221158ee243f37b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116623
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/vcl/uiconfig/ui/printdialog.ui b/vcl/uiconfig/ui/printdialog.ui
index b173e22..f289f48 100644
--- a/vcl/uiconfig/ui/printdialog.ui
+++ b/vcl/uiconfig/ui/printdialog.ui
@@ -1437,6 +1437,11 @@
        </child>
      </object>
    </child>
    <action-widgets>
      <action-widget response="-11">help</action-widget>
      <action-widget response="-5" default="true">ok</action-widget>
      <action-widget response="-6">cancel</action-widget>
    </action-widgets>
    <child internal-child="accessible">
      <object class="AtkObject" id="PrintDialog-atkobject">
        <property name="AtkObject::accessible-description" translatable="yes" context="printdialog|extended_tip|PrintDialog">Prints the current document, selection, or the pages that you specify. You can also set the print options for the current document.</property>
diff --git a/vcl/unx/gtk3/gtkinst.cxx b/vcl/unx/gtk3/gtkinst.cxx
index f581d71..45dae000 100644
--- a/vcl/unx/gtk3/gtkinst.cxx
+++ b/vcl/unx/gtk3/gtkinst.cxx
@@ -21458,6 +21458,9 @@ ConvertResult Convert3To4(const Reference<css::xml::dom::XNode>& xNode)
                                }
                            }

                            auto xUseHeaderBar = CreateProperty(xDoc, "use-header-bar", "1");
                            SetPropertyOnTopLevel(xContentAreaCandidate, xUseHeaderBar);

                            break;
                        }
                        xContentAreaCandidate = xContentAreaCandidate->getParentNode();