Adding build tools for gRPC compilation.
ONOS-6095

Change-Id: I80687eb2a91ad60c4dbec0bb966e917555d46151
diff --git a/buck-tools/default.defs b/buck-tools/default.defs
index d70cc37..ad9f8aa 100644
--- a/buck-tools/default.defs
+++ b/buck-tools/default.defs
@@ -4,6 +4,7 @@
 include_defs('//bucklets/onos_app.bucklet')
 include_defs('//bucklets/yang.bucklet')
 include_defs('//bucklets/remote_jar.bucklet')
+include_defs('//bucklets/grpc.bucklet')
 
 BASE_DEPS = [
     '//lib:junit',