[improve][schema] Improve Incompatible Schema Exception error message in ServerCnx.java

[nikam14]

Motivation

When schemavalidaitonenforced is enabled on topic and producer without schema is created on topic then IncompatibleSchemaException is thrown.
When producer without schema is created then by default bytes schema is added to producer.
In error message topic-schema and schemavalidationenforced=enabled is not specified.
After specifying schemavalidaitonenforced=enabled producer will be created with same schema.

Modifications

Modified the error message with specifying that schemaValidaitonEnforced is enabled.

Verifying this change

• Make sure that the change passes the CI checks.

This change is already covered by existing tests.

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:

[lhotari]

LGTM

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.58%. Comparing base (bbc6224) to head (a134c67).
Report is 603 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #23344      +/-   ##
============================================
+ Coverage     73.57%   74.58%   +1.01%     
- Complexity    32624    33939    +1315     
============================================
  Files          1877     1934      +57     
  Lines        139502   144981    +5479     
  Branches      15299    15839     +540     
============================================
+ Hits         102638   108138    +5500     
+ Misses        28908    28563     -345     
- Partials       7956     8280     +324     

Flag	Coverage Δ
inttests	27.57% <ø> (+2.98%)	⬆️
systests	24.56% <ø> (+0.23%)	⬆️
unittests	73.95% <ø> (+1.10%)	⬆️

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Files with missing lines	Coverage Δ
...va/org/apache/pulsar/broker/service/ServerCnx.java	72.56% <ø> (+0.42%)	⬆️

... and 599 files with indirect coverage changes