Add CI for testing rules_java with WORKSPACE only (no bzlmod)

PiperOrigin-RevId: 696033105
Change-Id: I01aeb15fe709244c9f2ea1200a23f1884f044fd5

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index cbe4e80..49422df 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -41,6 +41,10 @@
 
 rules_java_dependencies()
 
+load("@com_google_protobuf//bazel/private:proto_bazel_features.bzl", "proto_bazel_features")  # buildifier: disable=bzl-visibility
+
+proto_bazel_features(name = "proto_bazel_features")
+
 rules_java_toolchains()
 
 load("@stardoc//:setup.bzl", "stardoc_repositories")