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/protocols/p4runtime/ctl/BUILD b/protocols/p4runtime/ctl/BUILD
index 628d162..5f8db80 100644
--- a/protocols/p4runtime/ctl/BUILD
+++ b/protocols/p4runtime/ctl/BUILD
@@ -5,7 +5,7 @@
     "//protocols/p4runtime/api:onos-protocols-p4runtime-api",
     "//protocols/p4runtime/proto:onos-protocols-p4runtime-proto",
     "//lib:com_google_protobuf_protobuf_java",
-    "//lib:io_grpc_grpc_core_context",
+    "//lib:io_grpc_grpc_api_context",
     "//lib:io_grpc_grpc_netty",
     "//lib:io_grpc_grpc_protobuf_lite",
     "//lib:io_grpc_grpc_stub",
@@ -14,7 +14,9 @@
 
 TEST_DEPS = TEST + [
     "@minimal_json//jar",
-    "//lib:io_grpc_grpc_core_context",
+    "//lib:io_grpc_grpc_api_context",
+    "//lib:io_grpc_grpc_core_internal",
+    "//lib:io_grpc_grpc_core_inprocess",
     "//lib:io_grpc_grpc_protobuf_lite",
 ]