is
Finds out whether all consent items have been disallowed by the user. If, on the other hand, consent items are present, then processing will be carried out and false will be returned if at least one of them is not disallowed.
Important: If no consent item is present when calling this method no processing will be performed and null will be returned.
Return
true if all are disallowed, false if at least one consent item is not disallowed and null if no consent items is present