Fix service clients for kwargs as None or 0

images_client and servers_client, does not allow
to pass 0/none/false etc for few requetst param.

Service client interfaces should check existence if
those in kwargs instead of their value and
then populate the request body arg.

Change-Id: I40f5ef84ab90509722b485a5f38a97d8fbc1d37c
2 files changed