Backport uplink-status-propagation to ussuri/stable

[Danny Cocks]

The commit [1] introduced a config option `uplink-status-propagation` to support the neutron plugin `uplink_status_propagation`, available since the stein release of neutron, solving bug [2]. However it hasn't been included into the stable releases of charm-neutron-api until stable/yoga.

This is a problem for one of our customers and we'd like to backport this option to at least the stable/ussuri branch.

I would assume we should also do this for:

- stable/stein
- stable/train
- stable/victoria
- stable/wallaby
- stable/xena

The original bug which was solved by the above commit is:

[1] https://git.launchpad.net/charm-neutron-api/commit/?id=3e387d591869b714be1c323f240fcaff289b3c10
[2] https://bugs.launchpad.net/charm-neutron-api/+bug/1949491

[Felipe Reyes (freyes)]

hi Danny, I will mark this bug as duplicate of 1949491, although I will target the other bug to the series you would like to see the patch backported to.

[Danny Cocks (dannycocks)]

Thanks Felipe!