Add validation_resources in test_resize_volume_backed_server_confirm

Create_test_server in test_resize_volume_backed_server_confirm didn't
use validation_resources nor validatable=True, which resulted in an
SSHTimeout error when using fixed IP for connect_method.

When using connect_method=floating, the validation check refers
to the server created in setUp instead of this one, which prevented
this bug from being caught.

Change-Id: I778236f456ef91e78a592f99e552cb3088b1e5db
Co-authored-by: zhufl <zhu.fanglei@zte.com.cn>
Closes-Bug: #1751418
1 file changed