Move grpc-java to MODULE.bazel, bump to 1.62.2

grpc-java only got MODULE.bazel support as of this most recent version:

- grpc/grpc-java#11046
- bazelbuild/bazel-central-registry#1699

This grpc-java version bump exposed two issues that are fixed in this
commit:

1. The //java/com/engflow/notificationqueue:client target dependency on
   @maven//:io_netty_netty_handler broke.

   The original WORKSPACE import of io_grpc_grpc_java imported this
   dependency directly by passing IO_GRPC_GRPC_JAVA_ARTIFACTS directly
   to `maven_install`. The `maven.install` call from grpc/grpc-java's
   MODULE.bazel sets `strict_visibility = True`. Somehow the other
   dependencies registered by grpc-java's MODULE.bazel
   are accessible to notificationqueue:client, but netty-handler isn't.

   The solution was to add the `io.netty:netty-handler:4.1.100.Final`
   artifact to the `maven.install` call in this project's MODULE.bazel.
   It doesn't seem an optimal solution, but it works for now.

2. grpc/grpc-java removed `io.grpc.stub.MetadataUtils.attachHeaders()`
   in grpc/grpc-java#10443.

   This caused notificationqueue:client to fail to compile, but that PR
   revealed the replacement for the deprecated `attachHeaders` call.
   This commit applies that replacement.

MODULE.bazel

@@ -67,10 +67,29 @@ bazel_dep(name = "rules_java", version = "7.5.0")
 
 # https://github.com/bazelbuild/rules_jvm_external/blob/master/docs/bzlmod.md
 bazel_dep(name = "rules_jvm_external", version = "6.0")
+bazel_dep(
+    name = "grpc-java",
+    version = "1.62.2",
+    repo_name = "io_grpc_grpc_java",
+)
 
 # Loads rules required to compile proto files
 bazel_dep(name = "rules_proto_grpc", version = "5.0.0-alpha2")
 
+maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+maven.install(
+    artifacts = [
+        "commons-cli:commons-cli:1.5.0",
+        "com.google.oauth-client:google-oauth-client:1.34.1",
+        "io.netty:netty-handler:4.1.100.Final",
+    ],
+    strict_visibility = True,
+    repositories = [
+        "https://repo.maven.apache.org/maven2/",
+    ],
+)
+use_repo(maven, "maven")
+
 bazel_dep(
     name = "rules_swift",
     version = "1.18.0",