Replace ENSA2 sleep 300 with cs_wait_for_idle

Replace ENSA2 12sp5 sleep 300 with cs_wait_for_idle
TEAM-9458 - [timeboxed]Research is sleep 300 can be replaced with cs_wait_for_idle

tests/sles4sap/ensa/netweaver_ensa2_web_methods.pm

@@ -70,10 +70,9 @@ sub run {
     $self->webmethod_checks($instance_id);
     # Execute failover from ASCS instance - this will return resources to original host
     if ($instance_type eq 'ASCS') {
-        # Some delay needed here for 12-SP5, don't know why even webmethod_checks passed
+        # Use cs_wait_for_idle to wait until the cluster is idle before continuing the tests.
         if (is_sle('=12-SP5')) {
-            sleep 300;
-            record_info "sleep 300s for 12-SP5";
+            wait_for_idle_cluster(timeout => 300);
         }
         record_info('Failover', "Executing 'HAFailoverToNode'. Failover from $physical_hostname to remote site");
         $self->sapcontrol(webmethod => 'HAFailoverToNode', instance_id => $instance_id, additional_args => "\"\"");