[Backport to main]fix security IT failure caused by weak password (#951)

[zane-neo]

Description

Backport #951 to main
Reverted #1246 since the json structure changed.

Issues Resolved

[List any issues this PR will resolve]

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

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[codecov]

Codecov Report

Merging #1257 (f7d0ddd) into main (aa85254) will increase coverage by 0.01%.
Report is 4 commits behind head on main.
The diff coverage is 92.85%.

@@             Coverage Diff              @@
##               main    #1257      +/-   ##
============================================
+ Coverage     82.29%   82.30%   +0.01%     
  Complexity     1915     1915              
============================================
  Files           149      149              
  Lines          7502     7501       -1     
  Branches        746      744       -2     
============================================
  Hits           6174     6174              
  Misses          986      986              
+ Partials        342      341       -1     

Flag	Coverage Δ
ml-commons	82.30% <92.85%> (+0.01%)	⬆️

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Files Changed	Coverage Δ
...ain/java/org/opensearch/ml/engine/ModelHelper.java	90.00% <75.00%> (+0.27%)	⬆️
...n/model_group/TransportUpdateModelGroupAction.java	87.50% <100.00%> (+0.68%)	⬆️