Fixes #21024

Motivation

Modify the process of update topic policy.

Make topic policy can be updated correctly when user use pulsar-admin to set policy

Modifications

1. Construct a new topicPolicy in internalSetRetention(), which make sure we do not update the value of policiesCache in two area. We only update policiesCache by SystemTopicBasedTopicPoliciesService#refreshTopicPoliciesCache
2. All the method about update topicPolicy in pulsar-admin, should respond success to client after policy is actually updated in policiesCache.
3. Retry in isRetentionUpdateSuccess(), because systemTopicReader maybe can not immediately read next PulsarEvent message.
4. Improve the test in TopicPoliciesTest to make the test cover more complicated pulsar-admin operation.

Verifying this change

• Make sure that the change passes the CI checks.

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

If the box was checked, please highlight the changes

• 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: TakaHiR07#13