Bump grpc-java to 1.18.0

Requires bumping other dependencies in deps.json such as Netty (4.1.32)
and error_prone_annotations. Includes also fixes detected by updated
errorprone.

Change-Id: Ic2bd86931cc89bfb2cf1a4cb11a4586bc8cac608
diff --git a/tools/build/bazel/grpc_workspace.bzl b/tools/build/bazel/grpc_workspace.bzl
index 8b1e169..11b0b60 100644
--- a/tools/build/bazel/grpc_workspace.bzl
+++ b/tools/build/bazel/grpc_workspace.bzl
@@ -1,13 +1,13 @@
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("//tools/build/bazel:variables.bzl", "GRPC_JAVA_VERSION")
 
-GRPC_SHA = "d216c29f7e0eb4dce0192abbaaee9baf046a373805b6f45be3e5056ab0a616db"
+GRPC_SHA = "979cd1873c0f3aefa25f3d20336c023ce34471203bf2d954ad9e3158fc55c16b"
 
 GAPIS_COMMIT = "37cc0e5acae50ee91f00827a7010c3b07dfa5311"
 GAPIS_SHA = "17d023f48ea290f25edaf25a967973b5a42ce6d71b1570862f302d95aa8b9f77"
 
 def generate_grpc():
-    # Patched grpc-java that fixes the OSGi split problem.
+    # grpc-java fork that fixes the OSGi split problem.
     http_archive(
         name = "io_grpc_grpc_java",
         urls = ["https://github.com/opennetworkinglab/grpc-java/archive/v%s-patched.zip" % GRPC_JAVA_VERSION],