Upgrade cert manager to 0.16.0

[gyliu513]

Please check https://bugzilla.redhat.com/show_bug.cgi?id=1853600 for detail.

I can see the current cert manager version is 0.10.5 https://github.com/IBM/ibm-cert-manager-operator/pull/76/files , we have a problem for the integration with RHACM, is it possible to upgrade cert manager to 0.16.0?

[swati-nair]

@gyliu513
We decided to upgrade it to 0.15.1 in Q3, but there is a breaking change w.r.t APIGroup and API versions of cert-manager resources, which made us to drop the upgrade plan for this release. So, right now, we are only investigating a way to avoid the breaking change and if we find a way, we would be able to upgrade next release.