Check interface is present in the VM

This patch enhances the method "wait_for_interface_status" from
tempest. Apart from checking the interface status returned by
Nova, this methods access the VM to check if the NIC interface
is already detected by the kernel.

Change-Id: I5e411c72e0b6a8d96535adb04ff15e903454141c
Closes-Bug: #1883095
diff --git a/neutron_tempest_plugin/common/utils.py b/neutron_tempest_plugin/common/utils.py
index 34e7464..f03762c 100644
--- a/neutron_tempest_plugin/common/utils.py
+++ b/neutron_tempest_plugin/common/utils.py
@@ -26,8 +26,10 @@
     from urllib import parse as urlparse
 
 import eventlet
+
 from tempest.lib import exceptions
 
+
 SCHEMA_PORT_MAPPING = {
     "http": 80,
     "https": 443,