[improve][doc] Remove javadoc reference to old default 30s ack timeout impl

[GerMoranBYON]

Master Issue: #19486

Motivation

Remove ambiguity around this setting being 30s default per the other docs

Modifications

Updated the javadoc to align with the current implementation and as described in other areas of the documentation.

Verifying this change

• Make sure that the change passes the CI checks.

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

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:

[michaeljmarshall]

LGTM. Thanks @GerMoranOverstock!

[michaeljmarshall]

/pulsarbot rerun-failure-checks

[codecov-commenter]

Codecov Report

Merging #20377 (535cc35) into master (f20dc93) will increase coverage by 47.81%.
The diff coverage is 88.34%.

@@              Coverage Diff              @@
##             master   #20377       +/-   ##
=============================================
+ Coverage     25.11%   72.93%   +47.81%     
- Complexity      205    31894    +31689     
=============================================
  Files          1680     1864      +184     
  Lines        127176   138384    +11208     
  Branches      13863    15183     +1320     
=============================================
+ Hits          31942   100931    +68989     
+ Misses        90242    29446    -60796     
- Partials       4992     8007     +3015     

Flag	Coverage Δ
inttests	24.17% <29.12%> (?)
systests	24.96% <21.35%> (-0.15%)	⬇️
unittests	72.23% <88.34%> (?)

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

Impacted Files	Coverage Δ
...r/service/SystemTopicTxnBufferSnapshotService.java	83.01% <78.94%> (+83.01%)	⬆️
...r/impl/SnapshotSegmentAbortedTxnProcessorImpl.java	77.34% <88.23%> (+77.34%)	⬆️
...r/metadata/coordination/impl/ResourceLockImpl.java	78.87% <91.30%> (+45.33%)	⬆️
...er/impl/SingleSnapshotAbortedTxnProcessorImpl.java	80.61% <100.00%> (+80.61%)	⬆️
...java/org/apache/pulsar/common/util/FutureUtil.java	82.40% <100.00%> (+60.18%)	⬆️
...rg/apache/pulsar/common/util/URIPreconditions.java	83.33% <100.00%> (+83.33%)	⬆️
...ar/metadata/coordination/impl/LockManagerImpl.java	89.47% <100.00%> (+31.57%)	⬆️

... and 1540 files with indirect coverage changes

[tisonkun]

Merging...

Thanks for your contribution @GerMoranOverstock