AWS incorrectly handles bindings for placements

[Simon Richardson]

When working on https://bugs.launchpad.net/juju/+bug/1878202 it became apparent that AWS doesn't correctly handle binding placements, yet it does work with constraints.

Essentially this should work:

    juju bootstrap aws aws-test
    juju add-space space-1 172.31.32.0/20
    juju deploy cs:percona-cluster-290 --bind "space-1"

The provisioning info does return the correct details or at least enough information to handle that situation, but fails to do so.

Instead this does work:

    juju deploy postgresql --bind "space-1" --constraints="spaces=space-1"

[Simon Richardson (simonrichardson)]

PR: https://github.com/juju/juju/pull/11684