Description of problem (please be detailed as possible and provide log
snippests):
When blocking a target bucket's IO using a bucket policy, the NooBaa backingstore should show as unhealthy.
However, it remains healthy for at least 30 minutes (didn't check longer intervals).
Only when writing new objects to the NooBucket, the backingstore then moves into an IO_ERROR stage. 

The bucket policy I use - 
{
    "Version": "2012-10-17",
    "Id": "DenyReadWrite",
    "Statement": [
        {
            "Effect": "Deny",
            "Principal": {
                "AWS": "*"
            },
            "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:ListBucket"
            ],
            "Resource": [
                "arn:aws:s3:::BUCKETNAME/*",
                "arn:aws:s3:::BUCKETNAME"
            ]
        }
    ]
}


Version of all relevant components (if applicable):
ocs-operator.v4.4.0-413.ci
Also happened on 4.3.0-407.ci if I'm not wrong


Does this issue impact your ability to continue to work with the product
(please explain in detail what is the user impact)?
No

Is there any workaround available to the best of your knowledge?
Writing to the NB bucket forces the status to update and then shows the backingstore as unhealthy

Rate from 1 - 5 the complexity of the scenario you performed that caused this
bug (1 - very simple, 5 - very complex)?
2

Can this issue reproducible?
Yes


If this is a regression, please provide more details to justify this:
The backingstore used to move to a `AUTH_ERROR` status after a few minutes in the past, now it just remains healthy

Steps to Reproduce:
1. Create a backingstore
2. Block all IO on the target bucket using a bucket policy
3. See that the backingstore remains healthy


Actual results:
Backingstore is shown as healthy

Expected results:
Backingstore is shown as unhealthy

Additional info: