[Backport 2.x] fix ML task index mapping · opensearch-project/ml-commons@2e3dd45

The job was canceled because "_21" failed.

class org.apache.logging.log4j.simple.SimpleLoggerContext cannot be cast to class org.apache.logging.log4j.core.LoggerContext (org.apache.logging.log4j.simple.SimpleLoggerContext and org.apache.logging.log4j.core.LoggerContext are in unnamed module of loader 'app')

The operation was canceled.