Required. Name of the organization to list notification
configs. Its format is "organizations/[organization_id]".
The value returned by the last
``ListNotificationConfigsResponse``; indicates that this is
a continuation of a prior ``ListNotificationConfigs`` call,
and that the system should return the next page of data.
The maximum number of results to return in a
single response. Default is 10, minimum is 1,
maximum is 1000.