Extend the demo server.py to take a custom aggregation protocol

PiperOrigin-RevId: 722615196

Author: sdierauf

tensorflow_federated/cc/core/impl/aggregation/tensorflow/python/BUILD

@@ -26,6 +26,8 @@ pybind_extension(
     deps = [
         "//tensorflow_federated/cc/core/impl/aggregation/protocol:aggregation_protocol",
         "//tensorflow_federated/cc/core/impl/aggregation/protocol:configuration_cc_proto",
+        "//tensorflow_federated/cc/core/impl/aggregation/protocol:federated_compute_checkpoint_builder",
+        "//tensorflow_federated/cc/core/impl/aggregation/protocol:federated_compute_checkpoint_parser",
         "//tensorflow_federated/cc/core/impl/aggregation/protocol:resource_resolver",
         "//tensorflow_federated/cc/core/impl/aggregation/protocol/simple_aggregation",
         "//tensorflow_federated/cc/core/impl/aggregation/tensorflow:tensorflow_checkpoint_builder_factory",