[fix][broker] Inconsistent behaviour for topic auto_creation

[mattisonchao]

Motivation

Auto-creation topics mechanism relies on namespace policies which are very important for the broker to determine if we should auto create partitioned topic or non-partitioend topic.

We can't rely on the cache to get the random result. We should always load data from zk if the cache is missed to avoid fallback to broker default configuration.

e.g. If the metadata cache is missed, the logic will fallback to use broker configuration.

Broker configuration:

allowAutoTopicCreation=true
allowAutoTopicCreationType=non-partitioned

Namespace policies:

allowAutoTopicCreation=true
allowAutoTopicCreationType=partitioned

Modifications

• Load cache if the policy does not exist in the metadata cache.
• Change some code style to pass checkstyle.

Verifying this change

• Make sure that the change passes the CI checks.

Documentation

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

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.09%. Comparing base (57fbee4) to head (6d43e56).
⚠️ Report is 1820 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #20843      +/-   ##
============================================
+ Coverage     72.97%   73.09%   +0.12%     
- Complexity    32157    32176      +19     
============================================
  Files          1868     1868              
  Lines        139164   139185      +21     
  Branches      15314    15315       +1     
============================================
+ Hits         101555   101742     +187     
+ Misses        29562    29373     -189     
- Partials       8047     8070      +23     

Flag	Coverage Δ
inttests	24.16% <75.00%> (?)
systests	25.10% <75.00%> (+0.05%)	⬆️
unittests	72.40% <100.00%> (+0.01%)	⬆️

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

Files with missing lines	Coverage Δ
...rg/apache/pulsar/broker/service/BrokerService.java	81.74% <100.00%> (-0.08%)	⬇️

... and 87 files with indirect coverage changes

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