NAS backup: keep the Failed row when the agent reports a failed backup

#13180 made takeBackup keep the backup row in Failed state instead of
deleting it. The forward merge of 4.22 after #14305 resolved the
failed-answer branch to the 4.22 version, which deletes the row again.
Restore the update and return the row to the caller as the Error branch
does, so the schedule, name and resource counts are recorded on it.

Author: abh1sar

plugins/backup/nas/src/main/java/org/apache/cloudstack/backup/NASBackupProvider.java

@@ -669,8 +669,8 @@ public Pair<Boolean, Backup> takeBackup(final VirtualMachine vm, Boolean quiesce
                 return new Pair<>(false, backupVO);
             }
             backupVO.setStatus(Backup.Status.Failed);
-            backupDao.remove(backupVO.getId());
-            return new Pair<>(false, null);
+            backupDao.update(backupVO.getId(), backupVO);
+            return new Pair<>(false, backupVO);
         }
     }
 

plugins/backup/nas/src/test/java/org/apache/cloudstack/backup/NASBackupProviderTest.java

@@ -311,7 +311,7 @@ public void takeBackupFailureNeedingCleanupReturnsErrorBackup() throws AgentUnav
     }
 
     @Test
-    public void takeBackupFailureWithoutCleanupRemovesBackup() throws AgentUnavailableException, OperationTimedoutException {
+    public void takeBackupFailureWithoutCleanupKeepsFailedBackup() throws AgentUnavailableException, OperationTimedoutException {
         VMInstanceVO vm = mockRunningVmForBackup(1L, 2L, 3L, 4L, 5L, 6L);
 
         BackupAnswer answer = mock(BackupAnswer.class);
@@ -324,8 +324,10 @@ public void takeBackupFailureWithoutCleanupRemovesBackup() throws AgentUnavailab
         Pair<Boolean, Backup> result = nasBackupProvider.takeBackup(vm, false, false);
 
         Assert.assertFalse(result.first());
-        Assert.assertNull(result.second());
-        Mockito.verify(backupDao).remove(Mockito.anyLong());
+        Assert.assertNotNull(result.second());
+        Assert.assertEquals(Backup.Status.Failed, result.second().getStatus());
+        Mockito.verify(backupDao).update(Mockito.anyLong(), Mockito.any(BackupVO.class));
+        Mockito.verify(backupDao, Mockito.never()).remove(Mockito.anyLong());
         Mockito.verifyNoInteractions(alertManager);
     }