Remove orphaned field from operandconfig

[qpdpQ]

What this PR does / why we need it:
Remove orphaned field from operandconfig, after user remove it from CommonService CR.

Which issue(s) this PR fixes:
Fixes #
https://github.ibm.com/IBMPrivateCloud/roadmap/issues/68616
https://github.ibm.com/IBMPrivateCloud/roadmap/issues/69023

[qpdpQ]

Test image: quay.io/yuchen_li1/common-service-operator-amd64:remove-orphaned-field
Test log

I0324 20:11:21.290630       1 operandconfig.go:587] Removing orphaned fields from OperandConfig

After removing the following field about zenFrontDoor from cs cr

  services:
    - name: ibm-im-operator
      spec:
        authentication:
          config:
            zenFrontDoor: false

cr operator will remove it from operandconfig

[Daniel-Fan]

Thank you @qpdpQ

I just want to be cautious and do not wanna take the risk for un-stabilizing the 4.18 build since we are approaching Dcut.

Can we hold this PR and merge it for 4.19?