Adds `DifferentialyPrivateSumFactory` to the public API.

PiperOrigin-RevId: 338088240

tensorflow_federated/python/aggregators/BUILD

@@ -18,6 +18,7 @@ py_library(
     srcs_version = "PY3",
     visibility = ["//tensorflow_federated:__pkg__"],
     deps = [
+        ":dp_factory",
         ":factory",
         ":mean_factory",
         ":quantile_estimation",

tensorflow_federated/python/aggregators/__init__.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 """Libraries for constructing federated aggregation."""
 
+from tensorflow_federated.python.aggregators.dp_factory import DifferentiallyPrivateFactory
 from tensorflow_federated.python.aggregators.factory import AggregationProcessFactory
 from tensorflow_federated.python.aggregators.mean_factory import MeanFactory
 from tensorflow_federated.python.aggregators.quantile_estimation import PrivateQuantileEstimationProcess