Use default "ds512M" advance image in older stable branches

Those branches are not affected by the related bug. Furthermore,
those branches override the neutron-tempest-plugin version with an
older one that does not implement the method
"create_flavor_for_advance_image". This method is used to create a
specific flavor used in the CI tests.

Change-Id: Iad6fdfb3ebe7b5cafd8a1ee00724408abd7c17ff
Related-Bug: #1940243
4 files changed