chore: add configuration for protobuf-4.x-rc release (#11805)

Configuration in
https://github.com/googleapis/google-cloud-java/blob/protobuf-4.x-rc/release-please-config.json

---------

Co-authored-by: cloud-java-bot <[email protected]>

Author: diegomarquezp

.github/release-please.yml

@@ -33,3 +33,8 @@ branches:
     manifest: true
     handleGHRelease: true
     branch: 1.58.x
+  - primaryBranch: main
+    releaseType: java-yoshi
+    manifest: true
+    handleGHRelease: true
+    branch: protobuf-4.x-rc