fix parameter parsing bug for create connector input

[ylwu-amzn]

Description

If user input array parameter, the MLCreateConnectorInput will fail to parse. This PR fixed that bug.

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 #1185 (a86abf4) into 2.9 (82bddb1) will decrease coverage by 0.19%.
Report is 2 commits behind head on 2.9.
The diff coverage is 57.89%.

@@             Coverage Diff              @@
##                2.9    #1185      +/-   ##
============================================
- Coverage     78.92%   78.74%   -0.19%     
- Complexity     2119     2120       +1     
============================================
  Files           167      167              
  Lines          8633     8676      +43     
  Branches        869      870       +1     
============================================
+ Hits           6814     6832      +18     
- Misses         1423     1448      +25     
  Partials        396      396              

Flag	Coverage Δ
ml-commons	78.74% <57.89%> (-0.19%)	⬇️

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

Files Changed	Coverage Δ
...va/org/opensearch/ml/engine/utils/ScriptUtils.java	76.47% <ø> (ø)
...a/org/opensearch/ml/model/MLModelGroupManager.java	84.48% <ø> (ø)
.../main/java/org/opensearch/ml/utils/IndexUtils.java	41.17% <0.00%> (-22.46%)	⬇️
.../opensearch/ml/engine/encryptor/EncryptorImpl.java	91.04% <66.66%> (ø)
...java/org/opensearch/ml/rest/RestMLStatsAction.java	91.66% <78.94%> (-3.24%)	⬇️
...ch/ml/engine/algorithms/remote/ConnectorUtils.java	70.83% <87.50%> (+2.08%)	⬆️
...rg/opensearch/ml/plugin/MachineLearningPlugin.java	99.04% <100.00%> (+0.03%)	⬆️
...va/org/opensearch/ml/stats/MLClusterLevelStat.java	80.00% <100.00%> (+8.57%)	⬆️

... and 2 files with indirect coverage changes