AMBARI-7518. Add missed unit tests for clusterimpl.(vbrodetskyi)

ambari-server/src/test/java/org/apache/ambari/server/state/cluster/ClusterTest.java

@@ -57,6 +57,7 @@ import org.apache.ambari.server.orm.entities.ClusterServiceEntity;
 import org.apache.ambari.server.orm.entities.HostEntity;
 import org.apache.ambari.server.orm.entities.HostStateEntity;
 import org.apache.ambari.server.orm.entities.ServiceDesiredStateEntity;
+import org.apache.ambari.server.orm.entities.ClusterStateEntity;
 import org.apache.ambari.server.state.AgentVersion;
 import org.apache.ambari.server.state.Alert;
 import org.apache.ambari.server.state.AlertState;
@@ -485,9 +486,12 @@ public class ClusterTest {
     return clusterEntity;
   }
   
-  @Ignore
+  @Test
   public void testClusterRecovery() throws AmbariException {
     ClusterEntity entity = createDummyData();
+    ClusterStateEntity clusterStateEntity = new ClusterStateEntity();
+    clusterStateEntity.setCurrentStackVersion("{\"stackName\":\"HDP\",\"stackVersion\":\"0.1\"}");
+    entity.setClusterStateEntity(clusterStateEntity);
     ClusterImpl cluster = new ClusterImpl(entity, injector);
     Service service = cluster.getService("HDFS");
     /* make sure the services are recovered */