compute get_server_ip() should have detailed server object

[Yang Youseok]

in tempest/api/compute/servers/test_server_actions.py, test_resize_volume_backed_server_confirm()

get_server_ip() accept server object which has 'addresses' field. But the passed server object is returned value from create(POST) API which does not have 'addresses' field.

At result, this test case failed emitting KeyError like below.

=============================
Failed 1 test - output below:
=============================

tempest.api.compute.servers.test_server_actions.ServerActionsTestJSON.test_resize_volume_backed_server_confirm
--------------------------------------------------------------------------------------------------------------
Traceback (most recent call last):
  File "tempest/lib/decorators.py", line 112, in wrapper
    raise exc
KeyError: 'addresses'

======
Totals
======

Ran: 1 tests in 44.858 sec.
 - Success: 0
 - Skipped: 0
 - Expected failures: 0
 - Unexpected success: 0
 - Failures: 1

Furthermore, this test case also has another bug in that it was trying to validate server which was made without validation related flag (validatable,validation_resources). SSH connection was not completed since it does not have keypair (RemoteClient has no password so keypair is only way to be used)