### Description

Currently, when we execute retention policy, we also refresh the destination index by setting:
```
setRefresh(true)
```
on the DBQ request.
This can cause permission errors which are surprising to the user as the permissions are not required when the transform starts:
```
task encountered irrecoverable failure: org.elasticsearch.ElasticsearchSecurityException: action [indices:admin/refresh] is unauthorized for user [found-internal-kibana4-server] with roles [kibana_system,found-internal-kibana4-server] on indices [logs-cloud_security_posture.findings_latest-default], this action is granted by the index privileges [maintenance,manage,all]
```

We still want the user to have the permissions to delete the documents. But we should execute `refresh` as the system user.
x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformIndexer.java
}
        if (completedCheckpoint == 0) {
            return true;
        }
        int log10Checkpoint = (int) Math.floor(Math.log10(completedCheckpoint));
        logEvery = log10Checkpoint >= 3 ? 1_000 : (int) Math.pow(10.0, log10Checkpoint);
        logCount = 0;
        return true;
    }
    private RunState determineRunStateAtStart() {
        
        if (nextCheckpoint.getCheckpoint() == 1 || isContinuous() == false) {
            return RunState.APPLY_RESULTS;
        }
        
        if (changeCollector == null || changeCollector.queryForChanges() == false) {
            return RunState.APPLY_RESULTS;
        }
        
        return RunState.IDENTIFY_CHANGES;
    }
    private void configurePageSize(Integer newPageSize) {
        initialConfiguredPageSize = newPageSize;
        
        if (initialConfiguredPageSize != null && initialConfiguredPageSize > 0) {
            pageSize = initialConfiguredPageSize;
        } else {
            pageSize = function.getInitialPageSize();
        }
    }