Add FedProx to the OSS API.

PiperOrigin-RevId: 413722250

tensorflow_federated/python/learning/algorithms/BUILD

@@ -18,7 +18,10 @@ py_library(
     srcs = ["__init__.py"],
     srcs_version = "PY3",
     visibility = ["//tensorflow_federated/python/learning:__pkg__"],
-    deps = [":client_scheduled_federated_averaging"],
+    deps = [
+        ":client_scheduled_federated_averaging",
+        ":fed_prox",
+    ],
 )
 
 py_library(

tensorflow_federated/python/learning/algorithms/__init__.py

@@ -14,3 +14,4 @@
 """Libraries providing implementations of federated learning algorithms."""
 
 from tensorflow_federated.python.learning.algorithms.client_scheduled_federated_averaging import build_client_scheduled_federated_averaging_process
+from tensorflow_federated.python.learning.algorithms.fed_prox import build_example_weighted_fed_prox_process