OpenShift Data Foundation (ODF) NooBaa Multicloud Object Gateway (MCG) w/Bucket Policy Failed to Upgrade [v4.15] - Error: Code=INVALID_SCHEMA_REPLY Message=INVALID_SCHEMA_REPLY SERVER system_api#/methods/read_system"

Issue

After upgrading to ODF v4.15 the NooBaa backingstore blocks the ODF upgrade as it remains in the Connecting Phase leaving the storagecluster.yaml in phase Progressing with the following error in the noobaa-core-0 logs:

^[[32mAug-1 13:32:10.002^[[35m [WebServer/38] ^[[31m[ERROR]^[[39m core.rpc.rpc_schema:: INVALID_SCHEMA_REPLY SERVER system_api#/methods/read_system ERRORS: [
  {
    instancePath: ^[[32m'/buckets/0/s3_policy'^[[39m,
    schemaPath: ^[[32m'#/required'^[[39m,
    keyword: ^[[32m'required'^[[39m,
    params: { missingProperty: ^[[32m'Statement'^[[39m },
    message: ^[[32m"must have required property 'Statement'"^[[39m,
    schema: [ ^[[32m'Statement'^[[39m, [length]: ^[[33m1^[[39m ],
    parentSchema: { 
      type: ^[[32m'object'^[[39m,
      required: [ ^[[32m'Statement'^[[39m, [length]: ^[[33m1^[[39m ],
      properties: {
        Version: { type: ^[[32m'string'^[[39m },
        Statement: {
          type: ^[[32m'array'^[[39m,