Description of problem:

After upgrading to 1.8.2-4 from v1.5.10 (old dex configuration), 'Log In Via Openshift' is not working.

This is coming from testing https://issues.redhat.com/browse/GITOPS-2761 

The iissue had been fixed with https://github.com/argoproj-labs/argocd-operator/pull/877 but it does not address the possibility of existing argocd-secret

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Install v1.5.10 from 1.8.2-4 build
2. Upgrade to v1.8.2
3. Get the URL for ArgoCD Ui by either navigating to Networking > Routes in the namespace of your ArgoCD instance or using the console application launcher 
4. Try to Log in Via Openshift 

Actual results:

Attached screenshot.

Expected results:

Log In Via Openshift should let you log into the ArgoCD UI

Reproducibility (Always/Intermittent/Only Once):

With old dex configuration, Always

Build Details:

Index image v4.10: registry-proxy.engineering.redhat.com/rh-osbs/iib:469014 
Index image v4.11: registry-proxy.engineering.redhat.com/rh-osbs/iib:469015 
Index image v4.12: registry-proxy.engineering.redhat.com/rh-osbs/iib:469016 
Index image v4.13: registry-proxy.engineering.redhat.com/rh-osbs/iib:469017 

Additional info (Such as Logs, Screenshots, etc):