TSK-1894: set manual priority to default in rest

lib/taskana-core/src/main/java/pro/taskana/task/api/models/TaskSummary.java

@@ -15,6 +15,8 @@ import pro.taskana.workbasket.api.models.WorkbasketSummary;
  */
 public interface TaskSummary {
 
+  public static int DEFAULT_MANUAL_PRIORITY = -1;
+
   /**
    * Returns the id of the {@linkplain Task}.
    *

lib/taskana-core/src/main/java/pro/taskana/task/internal/models/TaskSummaryImpl.java

@@ -21,8 +21,6 @@ import pro.taskana.workbasket.internal.models.WorkbasketSummaryImpl;
 /** Entity which contains the most important information about a Task. */
 public class TaskSummaryImpl implements TaskSummary {
 
-  private static final int DEFAULT_MANUAL_PRIORITY = -1;
-
   protected String id;
   protected String externalId;
   protected Instant received;

rest/taskana-rest-spring/src/main/java/pro/taskana/task/rest/models/TaskSummaryRepresentationModel.java

@@ -1,5 +1,7 @@
 package pro.taskana.task.rest.models;
 
+import static pro.taskana.task.api.models.TaskSummary.DEFAULT_MANUAL_PRIORITY;
+
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
@@ -59,7 +61,7 @@ public class TaskSummaryRepresentationModel
    * priority is automatically set to manualPriority. In this case, all computations of priority are
    * disabled. If the value of manualPriority is negative, Tasks are not prioritized manually.
    */
-  protected int manualPriority;
+  protected int manualPriority = DEFAULT_MANUAL_PRIORITY;
   /** The current task state. */
   protected TaskState state;
   /** The classification of this task. */

rest/taskana-rest-spring/src/test/java/pro/taskana/task/rest/TaskControllerIntTest.java

@@ -749,6 +749,32 @@ class TaskControllerIntTest {
     assertThat(responseDeleted.getStatusCode()).isEqualTo(HttpStatus.NO_CONTENT);
   }
 
+  @Test
+  void should_CreateTaskWithCorrectPriorityAndThenDeleteIt_When_NotSpecifyingManualPriority() {
+    TaskRepresentationModel taskRepresentationModel = getTaskResourceSample();
+
+    String url = restHelper.toUrl(RestEndpoints.URL_TASKS);
+    HttpEntity<TaskRepresentationModel> auth =
+        new HttpEntity<>(taskRepresentationModel, RestHelper.generateHeadersForUser("teamlead-1"));
+
+    ResponseEntity<TaskRepresentationModel> responseCreate =
+        TEMPLATE.exchange(url, HttpMethod.POST, auth, TASK_MODEL_TYPE);
+    assertThat(responseCreate.getStatusCode()).isEqualTo(HttpStatus.CREATED);
+    assertThat(responseCreate.getBody()).isNotNull();
+    // The classification of taskRepresentationModel with the key "L11010" has priority=1
+    assertThat(responseCreate.getBody().getPriority()).isEqualTo(1);
+    assertThat(responseCreate.getBody().getManualPriority()).isEqualTo(-1);
+
+    String taskIdOfCreatedTask = responseCreate.getBody().getTaskId();
+    String url2 = restHelper.toUrl(RestEndpoints.URL_TASKS_ID, taskIdOfCreatedTask);
+    HttpEntity<Object> auth2 = new HttpEntity<>(RestHelper.generateHeadersForUser("admin"));
+
+    ResponseEntity<TaskRepresentationModel> responseDeleted =
+        TEMPLATE.exchange(
+            url2, HttpMethod.DELETE, auth2, ParameterizedTypeReference.forType(Void.class));
+    assertThat(responseDeleted.getStatusCode()).isEqualTo(HttpStatus.NO_CONTENT);
+  }
+
   @Test
   void should_GetPriorityCorrectly_When_GettingTaskWithManualPriority() {
     String url =