message: Fix collective_all_reduce_strategy_test breakages
  We need to respect collective_key_base in local mode as well.
diff: @@ -250,7 +250,8 @@ class CollectiveAllReduceExtended(mirrored_strategy.MirroredExtended):
  self._worker_device = device_util.canonicalize("/device:CPU:0")
  self._host_input_device = numpy_dataset.SingleDevice(self._worker_device)
  - self._collective_keys = cross_device_utils.CollectiveKeys()
  + self._collective_keys = cross_device_utils.CollectiveKeys(
  + group_key_start=1 + CollectiveAllReduceStrategy._collective_key_base) # pylint: disable=protected-access
  self._cross_device_ops = cross_device_ops_lib.CollectiveAllReduce(
  devices=local_devices,
  group_size=len(local_devices),
  