Add missing integration_tests check to metricbeat xpack test (elastic…

…#15779)

This test was running with the unit test target and failing.

metricbeat/module/elasticsearch/test_elasticsearch.py

@@ -74,6 +74,7 @@ def test_metricsets(self, metricset):
  self.check_metricset("elasticsearch", metricset, self.get_hosts(), self.FIELDS +
  ["service"], extras={"index_recovery.active_only": "false"})
 
+ @unittest.skipUnless(metricbeat.INTEGRATION_TESTS, "integration test")
  def test_xpack(self):
  """
  elasticsearch-xpack module tests