Merge pull request #5404 from acozzette/cherry-pick-4650

Cherry-picked fix from PR #4650 into 3.6.x branch

protobuf.bzl

@@ -266,8 +266,8 @@ def internal_gen_well_known_protos_java(srcs):
   Args:
     srcs: the well known protos
   """
-  root = Label("%s//protobuf_java" % (REPOSITORY_NAME)).workspace_root
-  pkg = PACKAGE_NAME + "/" if PACKAGE_NAME else ""
+  root = Label("%s//protobuf_java" % (native.repository_name())).workspace_root
+  pkg = native.package_name() + "/" if native.package_name() else ""
   if root == "":
     include = " -I%ssrc " % pkg
   else: