OZG-4713 OZG-4719 rename test method

alfa-xdomea/src/test/java/de/ozgcloud/alfa/export/ExportServiceTest.java

@@ -529,7 +529,7 @@ class ExportServiceTest {
 	class TestGetFormEngineName {
 
 		@Test
-		void shouldReturnEmptyOnNullEingang() {
+		void shouldReturnEmptyStringOnNullEingang() {
 			var vorgang = VorgangWithEingangTestFactory.createBuilder().eingang(null).build();
 
 			var formEngineName = service.getFormEngineName(vorgang);