Barbican moved to support multiple keks instead of just one.
OpenStack-helm is failing if run againist Barbican after commit [1].
This patch allows specify multiple and fix compatible issue.
[1] cfba1c1ba8f3659e6de727c3f1c274052e9ccace
Closes-Bug: 2103757
Change-Id: I438ee144b2a0a089dfffedf59961c155d9815889