Adds Yogi to the API.

PiperOrigin-RevId: 412219459

tensorflow_federated/python/learning/optimizers/BUILD

@@ -76,6 +76,7 @@ py_library(
         ":optimizer",
         ":rmsprop",
         ":sgdm",
+        ":yogi",
     ],
 )
 

tensorflow_federated/python/learning/optimizers/__init__.py

@@ -20,3 +20,4 @@ from tensorflow_federated.python.learning.optimizers.optimizer import handle_ind
 from tensorflow_federated.python.learning.optimizers.optimizer import Optimizer
 from tensorflow_federated.python.learning.optimizers.rmsprop import build_rmsprop
 from tensorflow_federated.python.learning.optimizers.sgdm import build_sgdm
+from tensorflow_federated.python.learning.optimizers.yogi import build_yogi