[fix][client] Make DeadLetterPolicy & KeySharedPolicy serializable

[AnuragReddy2000]

Fixes #23704

Motivation

We use the pulsar client to consume messages from a Pulsar broker in a Storm topology. Recently, we encountered an issue where the deadLetterPolicy that we set on the PulsarSpout seems to be lost when the topology is started. Upon investigation, we found that this is due to the deadLetterPolicy attribute in ConsumerConfigurationData being marked as transient. This prevents us from utilising the dead letter queue feature in our topology.

Modifications

Made DeadLetterPolicy, KeySharedPolicy and Range classes implement the java.io.Serializable interface and removed the transient keyword from the corresponding fields in the ConsumerConfigurationData class. In addition, two tests were also modified / updated.

Verifying this change

• Make sure that the change passes the CI checks.

This change added tests and can be verified as follows:

• Extended existing unit test for the ConsumerConfigurationData class to validate the retention of deadLetterPolicy through serialization & deserialization.

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

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: AnuragReddy2000#1

[dao-jun]

oh, that is a unconventional use case I've been never seen. @lhotari Do you think is this change makes sense?

[lhotari]

LGTM, good work @AnuragReddy2000

[AnuragReddy2000]

/pulsarbot rerun-failure-checks

[AnuragReddy2000]

@lhotari A test is failing on this PR which did not fail on the PR that raised in my fork. I checked the test, I'm not sure how my changes may cause it to fail. What do you suggest I do here?