RATIS-2512. Fix unreleased zero-copy messages during gRPC service shutdown.

[slfan1989]

What changes were proposed in this pull request?

This pull request fixes a zero-copy request leak during gRPC service shutdown.

ZeroCopyMessageMarshaller may still hold pending or in-flight zero-copy request streams when the gRPC service is being closed. Previously, closing these tracked streams did not trigger the release logic for the corresponding zero-copy messages, which could cause ZeroCopyMetrics to report unreleased messages during cluster shutdown.

The proposed changes:

• Release tracked zero-copy messages when ZeroCopyMessageMarshaller.close() is called.
• Add close logic for gRPC protocol services that own zero-copy request marshallers.
• Explicitly close these protocol services in GrpcServicesImpl.closeImpl() before unregistering zero-copy metrics.
• Ensure the same GrpcServerProtocolService instance bound to the gRPC server is also closed during shutdown.

What is the link to the Apache JIRA

RATIS-2512. Fix unreleased zero-copy messages during gRPC service shutdown

How was this patch tested?

• This patch was tested with the following commands:

./mvnw -pl ratis-test -am -Pgrpc-tests -Dtest=TestGrpcZeroCopy,TestRaftAsyncWithGrpc#testWithLoadAsync test

• Both tests passed successfully.

[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running org.apache.ratis.grpc.TestRaftAsyncWithGrpc
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 26.141 s - in org.apache.ratis.grpc.TestRaftAsyncWithGrpc
[INFO] Running org.apache.ratis.grpc.util.TestGrpcZeroCopy
[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 21.272 s - in org.apache.ratis.grpc.util.TestGrpcZeroCopy
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 4, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] ------------------------------------------------------------------------

[szetszwo]

+1 the change looks good.

[szetszwo]

This is good catch! We never call zeroCopyRequestMarshaller.close() except for tests.