Publish a prebuilt jar with BEP protos to maven

### Description of the feature request:

In [bazel-bsp](https://github.com/JetBrains/bazel-bsp/) we have to pull the entire Bazel source code just to get the BEP protos. It would be much more convenient for us if you published the BEP java proto library to maven.

We use the following targets from Bazel:
```
"@googleapis//:google_devtools_build_v1_build_events_java_proto",
"@googleapis//:google_devtools_build_v1_publish_build_event_java_grpc",
"@googleapis//:google_devtools_build_v1_publish_build_event_java_proto",
"@io_bazel//src/main/protobuf:deps_java_proto",
"@io_bazel//src/main/protobuf:failure_details_java_proto",
"@io_bazel//src/main/protobuf:invocation_policy_java_proto",
"@io_bazel//src/main/java/com/google/devtools/build/lib/buildeventstream/proto:build_event_stream_java_proto",
"@io_bazel//third_party/grpc:grpc-jar_checked_in",
```

### Which category does this issue belong to?

Core

### What underlying problem are you trying to solve with this feature?

_No response_

### Which operating system are you running Bazel on?

_No response_

### What is the output of `bazel info release`?

_No response_

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_

Start with the BEP Java and gRPC targets listed in the issue and compare them with the artifacts needed by bazel-bsp. Confirm the required proto classes and dependencies, then define a Maven publication covering those targets. Done means bazel-bsp can consume the published artifacts without pulling the Bazel source tree.

Written by the indexing model from the issue text.