[Backport 2.x] Replace and block usages of org.apache.logging.log4j.util.Strings (#15238)

[cwperks]

Manual backport of #15238 to 2.x. There was a conflict in RestClientBuilderTestCase with the import of Header from Apache HttpClient v4 on 2.x vs Apache HttpClient v5 on main.

[github-actions]

❌ Gradle check result for 1af0a13: 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 1af0a13: SUCCESS

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 71.47%. Comparing base (e66bcdf) to head (1af0a13).
Report is 2 commits behind head on 2.x.

Files	Patch %	Lines
...teway/remote/RemoteClusterStateCleanupManager.java	0.00%	0 Missing and 2 partials ⚠️
.../main/java/org/opensearch/env/NodeEnvironment.java	0.00%	0 Missing and 1 partial ⚠️
...ain/java/org/opensearch/index/shard/ShardPath.java	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x   #15246      +/-   ##
============================================
- Coverage     71.56%   71.47%   -0.09%     
+ Complexity    62859    62806      -53     
============================================
  Files          5138     5138              
  Lines        295074   295074              
  Branches      42978    42979       +1     
============================================
- Hits         211168   210914     -254     
- Misses        66226    66509     +283     
+ Partials      17680    17651      -29     

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