Fix rules_java `metadata.template.json` for BCR

The `github_user_id` is now mandatory: https://buildkite.com/bazel/bcr-presubmit/builds/39168/table?jid=019febef-1d73-4158-9660-9cc6c02f9342&tab=output

PiperOrigin-RevId: 962131561
Change-Id: I98d7f7180682b4f9d9e67f7c67d6a7e3b52a165d

.bcr/metadata.template.json

diff --git a/.bcr/metadata.template.json b/.bcr/metadata.template.json
index 9d09144..8ef2f6a 100644
--- a/.bcr/metadata.template.json
+++ b/.bcr/metadata.template.json
@@ -4,7 +4,8 @@
     {
       "email": "hvd@google.com",
       "github": "hvadehra",
-      "name": "Hemanshu Vadehra"
+      "name": "Hemanshu Vadehra",
+      "github_user_id": 2486163
     }
   ],
   "versions": [],