chore: add release-please config for protobuf-4.x

Author: diegomarquezp

.github/release-please.yml

@@ -6,5 +6,12 @@ branches:
     handleGHRelease: true
     releaseType: java-yoshi
     branch: java7
+  - bumpMinorPreMajor: true
+    handleGHRelease: true
+    releaseType: java-yoshi
+    branch: protobuf-4.x-rc
+    manifest: true
+    extraFiles:
+    - src/main/java/com/google/cloud/logging/logback/LoggingAppender.java
 extraFiles:
   - src/main/java/com/google/cloud/logging/logback/LoggingAppender.java