Replace explicit type conversion with instanceof pattern variable in plugins dir and libs dir

[gaobinlong]

Description

Similar to #19714.

Use the modern instanceof pattern variables instead of explicit type conversions in all moduels, this can improve the code readability and reduce potential ClassCastException risks.

Related Issues

No issue.

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

❌ Gradle check result for 33e2d12: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[sandeshkr419]

LGTM!

Thanks @gaobinlong for putting efforts in refactoring this!

[github-actions]

❌ Gradle check result for 33e2d12: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❕ Gradle check result for 1f9ae8a: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

❌ Patch coverage is 76.86833% with 65 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.17%. Comparing base (a2e1fa2) to head (cbb78ef).
⚠️ Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
...n/annotation/processor/ApiAnnotationProcessor.java	73.33%	0 Missing and 8 partials ⚠️
...rg/opensearch/core/xcontent/MapXContentParser.java	68.75%	2 Missing and 3 partials ⚠️
...ava/org/opensearch/ingest/attachment/TikaImpl.java	16.66%	3 Missing and 2 partials ⚠️
...org/opensearch/plugin/ingestion/fs/FileOffset.java	0.00%	2 Missing and 2 partials ⚠️
.../opensearch/telemetry/OTelAttributesConverter.java	57.14%	2 Missing and 1 partial ⚠️
.../java/org/opensearch/common/bootstrap/JarHell.java	0.00%	1 Missing and 1 partial ⚠️
...a/org/opensearch/core/util/ConfigurationUtils.java	80.00%	1 Missing and 1 partial ⚠️
.../org/opensearch/core/xcontent/XContentBuilder.java	88.23%	1 Missing and 1 partial ⚠️
...n/java/org/opensearch/common/ssl/KeyStoreUtil.java	50.00%	0 Missing and 2 partials ⚠️
...ch/common/xcontent/json/JsonXContentGenerator.java	66.66%	0 Missing and 2 partials ⚠️
... and 22 more

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #20012      +/-   ##
============================================
- Coverage     73.27%   73.17%   -0.11%     
+ Complexity    71553    71483      -70     
============================================
  Files          5789     5789              
  Lines        327144   327112      -32     
  Branches      47156    47116      -40     
============================================
- Hits         239715   239353     -362     
- Misses        68235    68517     +282     
- Partials      19194    19242      +48     

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[gaobinlong]

❌ Gradle check result for 33e2d12: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

Need to handle potential NPE for switch, will check previous refactor PRs.

[github-actions]

❌ Gradle check result for cbb78ef: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

✅ Gradle check result for cbb78ef: SUCCESS