[netflow] Fix invalid Kibana search indexRefName reference

[taylor-swanson]

What does this PR do?

Fixes an invalid reference in a Kibana search saved object.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Related issues

• elastic/sdh-beats#2572

[elasticmachine]

🚀 Benchmarks report

Package netflow 👍(0) 💚(0) 💔(1)

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Data stream	Previous EPS	New EPS	Diff (%)	Result
log	26315.79	14492.75	-11823.04 (-44.93%)	💔

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💚 Build Succeeded

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Build stats

• Start Time: 2022-10-04T20:41:54.275+0000

• Duration: 15 min 42 sec

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Test	Results
Failed	0
Passed	91
Skipped	0
Total	91

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🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (1/1)	💚
Files	100.0% (1/1)	💚 2.573
Classes	100.0% (1/1)	💚 2.573
Methods	100.0% (7/7)	💚 9.819
Lines	100.0% (56/56)	💚 8.418
Conditionals	100.0% (0/0)	💚

[efd6]

LGTM; confirmed locally.