Fix retrieval of services from K8s manifests of a helm-based KDU

Change-Id: I31ca19f3484df4a74d5c06541f7409c57a7588d4
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_lcm/n2vc/k8s_helm3_conn.py b/osm_lcm/n2vc/k8s_helm3_conn.py
index 98f4beb..29e4349 100644
--- a/osm_lcm/n2vc/k8s_helm3_conn.py
+++ b/osm_lcm/n2vc/k8s_helm3_conn.py
@@ -338,14 +338,11 @@
             cluster_name=cluster_id, create_if_not_exist=True
         )
 
-        command1 = "env KUBECONFIG={} {} get manifest {} --namespace={}".format(
+        command = "env KUBECONFIG={} {} get manifest {} --namespace={}".format(
             kubeconfig, self._helm_command, quote(kdu_instance), quote(namespace)
         )
-        command2 = "{} get --namespace={} -f -".format(
-            self.kubectl_command, quote(namespace)
-        )
-        output, _rc = await self._local_async_exec_pipe(
-            command1, command2, env=env, raise_exception_on_error=True
+        output, _rc = await self._local_async_exec(
+            command, env=env, raise_exception_on_error=True
         )
         services = self._parse_services(output)