[improve][broker] Make timer execute immediately after load index

[coderzc]

PIP: #16763

Motivation & Modifications

Make the timer execute immediately after the load index.
Improve method name

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

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

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Documentation

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Matching PR in forked repository

PR in forked repository:

[cbornet]

@coderzc we're in code freeze for 3.0. Is this a blocker or fixing a regression from 2.11 ? Otherwise I suggest to move this to 3.1 milestone.

[coderzc]

@coderzc we're in code freeze for 3.0. Is this a blocker or fixing a regression from 2.11 ? Otherwise I suggest to move this to 3.1 milestone.

OK, it can be moved to 3.1

[codecov-commenter]

Codecov Report

Merging #20126 (0b14ed5) into master (b50e880) will increase coverage by 35.20%.
The diff coverage is 72.00%.

@@              Coverage Diff              @@
##             master   #20126       +/-   ##
=============================================
+ Coverage     37.75%   72.95%   +35.20%     
- Complexity    12534    31920    +19386     
=============================================
  Files          1691     1868      +177     
  Lines        128811   138359     +9548     
  Branches      14045    15226     +1181     
=============================================
+ Hits          48632   100944    +52312     
+ Misses        73850    29398    -44452     
- Partials       6329     8017     +1688     

Flag	Coverage Δ
inttests	24.23% <0.00%> (+0.06%)	⬆️
systests	24.96% <0.00%> (-0.02%)	⬇️
unittests	72.22% <72.00%> (+39.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...xtensions/channel/ServiceUnitStateChannelImpl.java	83.79% <ø> (+83.21%)	⬆️
.../org/apache/pulsar/PulsarClusterMetadataSetup.java	72.51% <33.33%> (+55.54%)	⬆️
...ns/channel/ServiceUnitStateCompactionStrategy.java	80.95% <83.33%> (+70.42%)	⬆️
...n/java/org/apache/pulsar/broker/PulsarService.java	82.08% <100.00%> (+12.43%)	⬆️
...r/delayed/bucket/BucketDelayedDeliveryTracker.java	84.17% <100.00%> (+84.17%)	⬆️
.../pulsar/compaction/StrategicTwoPhaseCompactor.java	76.49% <100.00%> (+1.70%)	⬆️
...a/org/apache/pulsar/client/impl/TableViewImpl.java	86.29% <100.00%> (+34.22%)	⬆️

... and 1419 files with indirect coverage changes

[RobertIndie]

@coderzc
I think this is moved to the 3.1.0 milestone. But why did you cherry-pick it to branch-3.0? Am I missing any context here?