1.1: Update downstream OLM channels to support different x and y-stream releases

Currently we publish all of our downstream releases to a `stable` channel. This is going to cause issues for partners/customers in the future if they need to pin to a specific y-stream release (such as ACM requires cc vbirsan@redhat.com ). 

We need to ensure we update to include a `stable-1.1` channel which only contains 1.1.x releases.