code: private DescribeAvailabilityZonesResponseType describeAvailabilityZones() {
          DescribeAvailabilityZonesResponseType ret = new DescribeAvailabilityZonesResponseType();
          ret.setRequestId(UUID.randomUUID().toString());
  
          AvailabilityZoneSetType info = new AvailabilityZoneSetType();
  
          AvailabilityZoneItemType item = new AvailabilityZoneItemType();
          item.setRegionName(currentRegion);
          item.setZoneName(currentRegion);
          info.getItem().add(item);
          ret.setAvailabilityZoneInfo(info);
          return ret;
      }
docs: Handles "describeAvailabilityZones" request, as simple as without any filters to use.
  
  @return a DescribeAvailabilityZonesResponseType with our predefined AMIs
  in aws-mock.properties (or if not overridden, as defined in aws-mock-default.properties)