Rename @maven -> @google_bazel_common_maven

[lamcw]

Non-root modules should not use maven as the name of maven closure as it can create duplicate artifacts/conflicts with other closure (and most importantly the closure created in the root module) -- see https://github.com/bazel-contrib/rules_jvm_external/issues/916.

This PR creates a custom namespace for maven jars that is used within google_bazel_common, following similar patterns in

• protobuf https://github.com/protocolbuffers/protobuf/pull/18641
• rules_jvm_external, and
• rules_kotlin

[lamcw]

@netdpb what else do I need to do to get this merged?

[netdpb]

@netdpb what else do I need to do to get this merged?

Nothing. We had to go through our internal merge process. Thanks for your work!