Add support for upgrade of cert-manager

[anaik91]

Is your feature request related to a problem? Please describe.
When upgrading Apigee hybrid , cert-manager may needs to be upgarded

Describe the solution you'd like
Ability to upgrade the cert-manager when version is bumped in vars fiie

Describe alternatives you've considered
NA
Additional context
NA

[zvdy]

Have a look at this branch I'm unable to test properly due to the lack of an Cloud environment but feel free to test it yourself and modify if needed

Main change is under roles/cert-manager/tasks/main.yml

I will open a PR if successful