Update protobuf packages to v4.28.2 (#486)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Jason Plumb <[email protected]>

Author: renovate[bot]

grpc/build.gradle.kts

@@ -16,15 +16,15 @@ java {
 }
 
 var grpcVersion = "1.66.0" // CURRENT_GRPC_VERSION
-var protobufVersion = "4.28.0"
+var protobufVersion = "4.28.2"
 var protocVersion = protobufVersion
 
 dependencies {
     runtimeOnly ("io.grpc:grpc-netty-shaded:${grpcVersion}")
     implementation ("io.grpc:grpc-protobuf:${grpcVersion}")
     implementation ("io.grpc:grpc-services:${grpcVersion}")
     implementation ("io.grpc:grpc-stub:${grpcVersion}")
-    implementation ("com.google.protobuf:protobuf-java-util:4.28.0")
+    implementation ("com.google.protobuf:protobuf-java-util:${protobufVersion}")
     implementation ("io.opentelemetry.instrumentation:opentelemetry-grpc-1.6:1.32.0-alpha")
     implementation ("com.google.guava:guava:33.3.0-jre")