change which control plane revision handles injection, it's possible to create a revision tag "prod" and label our
namespace "istio.io/rev=prod". The "prod" revision tag could point to "1-7-6" initially and then be changed to point to "1-8-1"
at some later point.

This allows operators to change which Istio control plane revision should handle injection for a namespace or set of namespaces
without manual relabeling of the "istio.io/rev" tag.
`,