Managed Service for Apache Spark (formerly Dataproc on Compute Engine)

## Feature Feature **Managed Service for Apache Spark** (formerly Dataproc on Compute Engine): * The `2.1`, `2.2` and `2.3` cluster image versions now support[Confidential Compute](https://docs.cloud.google.com/managed-spark/docs/concepts/configuring-clusters/confidential-compute)for the[g4-standard-48](https://docs.cloud.google.com/compute/docs/gpus#rtx-6000-gpus)GPU machine type. ## Change Change **Managed Service for Apache Spark** (formerly Google Cloud Serverless for Apache Spark): * The [3.0 runtime](https://docs.cloud.google.com/managed-spark/docs/concepts/versions/spark-runtime-3.0)now uses fewer executors, as follows: * 0 min executors for `spark.dynamicAllocation.minExecutors` property * 1 min executor for `spark.executor.instances` and `spark.dynamicAllocation.initialExecutors` properties * All runtimes now configure `spark.scheduler.listenerbus.exitTimeout` to `30` seconds.