[DDF] specify a namespace or this command will hang and the CO deployment won't get created

I think it's essential to specify a namespace or this command will hang and the CO deployment won't get created.

oc apply -f install/cluster-operator/ --namespace my-project

Reported by: dlaing

https://access.redhat.com/documentation/en-us/red_hat_amq/2021.q3/html/evaluating_amq_streams_on_openshift/assembly-evaluation-str#annotations:ecc7fa4e-7cc7-40ef-97ce-ffce863080ac