First attempt at supporting builds with Java 11

Includes:
- Bump protobuf to 3.8.0 and grpc-java to 1.21.0 (along with transitive
  dependencies such as Netty)
- Add jaxb_api at compile time when needed (removed in JDK 11)
- Bump Bnd to 4.1 (adds support for Java 11)

To build with JDK 11, uncomment lines in .bazelrc.
Tested with Bazel 0.26.0.

Change-Id: Ib8e0c7310eacf97328762606e57c01e4834e5565
diff --git a/tools/build/publish-target-list b/tools/build/publish-target-list
index 992ed6c..ebe182c 100644
--- a/tools/build/publish-target-list
+++ b/tools/build/publish-target-list
@@ -48,6 +48,6 @@
     //utils/rest:onlab-rest
     //web/api:onos-rest
     //lib:com_google_protobuf_protobuf_java
-    //lib:io_grpc_grpc_core_context
+    //lib:io_grpc_grpc_api_context
     //lib:io_grpc_grpc_stub
     //lib:io_grpc_grpc_protobuf