Fix to docker import issues and swagger error

This is actually two fixes in one change:
1. Fixing the import issues in the docker containers, also cleaning
   it up.
2. Avoiding the creation of multiple swagger.json files by specifying
   which of the proto files represent the top-level service.

Change-Id: I9fec5cf48df127725673ba53f0e91d2ed2e275ad
diff --git a/ofagent/connection_mgr.py b/ofagent/connection_mgr.py
index b55d47a..17af7b2 100644
--- a/ofagent/connection_mgr.py
+++ b/ofagent/connection_mgr.py
@@ -23,7 +23,7 @@
 from common.utils.consulhelpers import get_endpoint_from_consul
 from structlog import get_logger
 import grpc
-# from ofagent.protos import third_party
+from ofagent.protos import third_party
 from protos import voltha_pb2
 from grpc_client import GrpcClient