add protobuf to workspace

Author: rickeylev

tests/integration/ignore_root_user_error/WORKSPACE

@@ -1,5 +1,12 @@
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
+http_archive(
+    name = "protobuf",
+    sha256 = "da288bf1daa6c04d03a9051781caa52aceb9163586bff9aa6cfb12f69b9395aa",
+    strip_prefix = "protobuf-27.0",
+    url = "https://github.com/protocolbuffers/protobuf/releases/download/v27.0/protobuf-27.0.tar.gz",
+)
+
 http_archive(
     name = "rules_cc",
     sha256 = "d9bdd3ec66b6871456ec9c965809f43a0901e692d754885e89293807762d3d80",