Bump to most recent protobuf-java

build.gradle

@@ -84,7 +84,7 @@ tasks.sourcesJar {
 javadoc { options.addStringOption('Xdoclint:none', '-quiet') }
 
 def grpcVersion = "1.66.0"
-def protocVersion = "4.27.4"
+def protocVersion = "4.28.0"
 def authzedProtoCommit = "v1.35.0"
 def bufDir = "${buildDir}/buf"
 def protocPlatformTag = project.findProperty('protoc_platform') ? ":${protoc_platform}" : ""