[Backport 2.9] renaming metrics

[opensearch-trigger-bot]

Backport 86eb953 from #1224

[codecov]

Codecov Report

Merging #1229 (468d543) into 2.9 (1ffd6a5) will increase coverage by 0.11%.
The diff coverage is 75.43%.

@@             Coverage Diff              @@
##                2.9    #1229      +/-   ##
============================================
+ Coverage     78.76%   78.88%   +0.11%     
- Complexity     2136     2140       +4     
============================================
  Files           168      168              
  Lines          8745     8741       -4     
  Branches        877      877              
============================================
+ Hits           6888     6895       +7     
+ Misses         1456     1446      -10     
+ Partials        401      400       -1     

Flag	Coverage Δ
ml-commons	78.88% <75.43%> (+0.11%)	⬆️

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

Files Changed	Coverage Δ
...h/ml/action/deploy/TransportDeployModelAction.java	82.73% <ø> (-0.13%)	⬇️
.../action/register/TransportRegisterModelAction.java	96.20% <ø> (-0.03%)	⬇️
.../java/org/opensearch/ml/task/MLTaskDispatcher.java	33.33% <0.00%> (+0.39%)	⬆️
...n/java/org/opensearch/ml/model/MLModelManager.java	62.97% <66.66%> (+0.18%)	⬆️
...pensearch/ml/task/MLTrainAndPredictTaskRunner.java	78.26% <66.66%> (ø)
...a/org/opensearch/ml/task/MLTrainingTaskRunner.java	59.25% <66.66%> (ø)
...h/ml/action/stats/MLStatsNodesTransportAction.java	93.10% <100.00%> (ø)
.../action/undeploy/TransportUndeployModelAction.java	78.57% <100.00%> (-0.22%)	⬇️
...rg/opensearch/ml/plugin/MachineLearningPlugin.java	99.05% <100.00%> (ø)
...java/org/opensearch/ml/rest/RestMLStatsAction.java	92.03% <100.00%> (+0.36%)	⬆️
... and 5 more

... and 2 files with indirect coverage changes