This patch fixes the response to POST requests in the metadata API so it
actually matches the documentation. [1]
Story: 2009247
Task: 43671
[1]
https://docs.openstack.org/barbican/latest/api/reference/secret_metadata.html#post-v1-secrets-uuid-metadata
Change-Id: I5505a8c56ed7274519cac8ad1e6d7adf5086c8d1
(cherry picked from commit 49f3b2f0d1)