Use assert_flavor_equal to check flavor before and after microversion 2.46

Flavor id is not returned in the server response after microversion 2.46,
but we can use base.assert_flavor_equal to check flavor before and after
microversion 2.46.

Change-Id: If04005a3ff5ef4b1faa4d2179ba2987abdd5ef04
diff --git a/tempest/api/compute/servers/test_server_actions.py b/tempest/api/compute/servers/test_server_actions.py
index f6c3e73..d47ff51 100644
--- a/tempest/api/compute/servers/test_server_actions.py
+++ b/tempest/api/compute/servers/test_server_actions.py
@@ -417,10 +417,7 @@
         waiters.wait_for_server_status(self.client, self.server_id, 'ACTIVE')
         # Make sure everything still looks OK.
         server = self.client.show_server(self.server_id)['server']
-        # The flavor id is not returned in the server response after
-        # microversion 2.46 so handle that gracefully.
-        if server['flavor'].get('id'):
-            self.assertEqual(self.flavor_ref, server['flavor']['id'])
+        self.assert_flavor_equal(self.flavor_ref, server['flavor'])
         attached_volumes = server['os-extended-volumes:volumes_attached']
         self.assertEqual(1, len(attached_volumes))
         self.assertEqual(volume['id'], attached_volumes[0]['id'])