[FLINK-34429] [flink-kubernetes] Adding K8S Annotations to Internal Service

[barakbn]

What is the purpose of the change

Flink currently supports adding Annotations to the Rest Service (with the configuration key: kubernetes.rest-service.annotations).

This PR adds a new configuration key: kubernetes.internal-service.annotations to allow the same functionality for the internal service.

Brief change log

(for example:)

• New configuration key: "kubernetes.internal-service.annotations" is added
• Configuration value is used in intenal-service creation
• Documentation is added

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: yes
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? yes
• If yes, how is the feature documented? docs

[flinkbot]

CI report:

• 0a06db7df6c1251c4f7006204cd336905c687079 UNKNOWN
• c34741810874c6ded36abd00ab82bbc950e2a2f7 Azure: SUCCESS

Bot commands

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• @flinkbot run azure re-run the last Azure build

[dannycranmer]

@barakbn please rebase and squash commits and I will merge.