Description of problem:

When deploying MTC on a OCP 4.6 cluster, the DPA fails to get created according to the logs, which results in some pods being missing. 

From the logs in the migration-controller in the OCP 4.6 cluster it indicates that an unexpected null value is passed which causes the error.


Version-Release number of selected component (if applicable):

MTC 1.7.8
OADP 1.0.8
OCP 4.6 --> OCP 4.10


How reproducible:
Always

Steps to Reproduce:
1. Provision a pair of clusters where one of them is OCP 4.6
2. Deploy mtc application


Actual results:

Actual resources DPA resource is not created


Expected results:

The MTC should be installed along with OADP and all their resources without any errors


Additional info:

This behavior is observed only on 4.6 clusters

When creating a DPA resource in the UI console, the resource is not created but the 
pods are created and running, and shows the error message ( see attached image )


from the logs:

 lastTransitionTime: "2023-02-27T12:44:08Z"
      message: 'Failed to create object: b''{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"DataProtectionApplication.oadp.openshift.io
        \\"velero\\" is invalid: [spec.unsupportedOverrides.awsPluginImageFqin: Invalid
        value: \\"null\\": spec.unsupportedOverrides.awsPluginImageFqin in body must
        be of type string: \\"null\\", spec.unsupportedOverrides.azurePluginImageFqin:
        Invalid value: \\"null\\": spec.unsupportedOverrides.azurePluginImageFqin
        in body must be of type string: \\"null\\", spec.unsupportedOverrides.gcpPluginImageFqin:
        Invalid value: \\"null\\": spec.unsupportedOverrides.gcpPluginImageFqin in
        body must be of type string: \\"null\\", spec.unsupportedOverrides.openshiftPluginImageFqin:
        Invalid value: \\"null\\": spec.unsupportedOverrides.openshiftPluginImageFqin
        in body must be of type string: \\"null\\", spec.unsupportedOverrides.resticRestoreImageFqin:
        Invalid value: \\"null\\": spec.unsupportedOverrides.resticRestoreImageFqin
        in body must be of type string: \\"null\\", spec.unsupportedOverrides.veleroImageFqin:
        Invalid value: \\"null\\": spec.unsupportedOverrides.veleroImageFqin in body
        must be of type string: \\"null\\", spec.configuration.velero.logLevel: Invalid
        value: \\"null\\": spec.configuration.velero.logLevel in body must be of type
        string: \\"null\\", spec.configuration.velero.logLevel: Unsupported value:
        \\"null\\": supported values: \\"trace\\", \\"debug\\", \\"info\\", \\"warning\\",
        \\"error\\", \\"fatal\\", \\"panic\\"]","reason":"Invalid","details":{"name":"velero","group":"oadp.openshift.io","kind":"DataProtectionApplication","causes":[{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.awsPluginImageFqin in body must
        be of type string: \\"null\\"","field":"spec.unsupportedOverrides.awsPluginImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.azurePluginImageFqin in body
        must be of type string: \\"null\\"","field":"spec.unsupportedOverrides.azurePluginImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.gcpPluginImageFqin in body must
        be of type string: \\"null\\"","field":"spec.unsupportedOverrides.gcpPluginImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.openshiftPluginImageFqin in body
        must be of type string: \\"null\\"","field":"spec.unsupportedOverrides.openshiftPluginImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.resticRestoreImageFqin in body
        must be of type string: \\"null\\"","field":"spec.unsupportedOverrides.resticRestoreImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.unsupportedOverrides.veleroImageFqin in body must
        be of type string: \\"null\\"","field":"spec.unsupportedOverrides.veleroImageFqin"},{"reason":"FieldValueInvalid","message":"Invalid
        value: \\"null\\": spec.configuration.velero.logLevel in body must be of type
        string: \\"null\\"","field":"spec.configuration.velero.logLevel"},{"reason":"FieldValueNotSupported","message":"Unsupported
        value: \\"null\\": supported values: \\"trace\\", \\"debug\\", \\"info\\",
        \\"warning\\", \\"error\\", \\"fatal\\", \\"panic\\"","field":"spec.configuration.velero.logLevel"}]},"code":422}\n'''
      reason: Failed
      status: "True"
      type: Failure