NIFI-14311 Fix Elasticsearch verification message checks

[exceptionfactory]

Summary

NIFI-14311 Corrects Elasticsearch Client integration test methods to avoid comparing exact verification message strings. Changes include removing some checks and replacing others with checking for a single keyword.

Tracking

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Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-00000
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-00000

Pull Request Formatting

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Verification

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Build

• Build completed using mvn clean install -P contrib-check
  • JDK 21

Licensing

• New dependencies are compatible with the Apache License 2.0 according to the License Policy
• New dependencies are documented in applicable LICENSE and NOTICE files

Documentation

• Documentation formatting appears as expected in rendered files

[joewitt]

nice +1