[Stack Monitoring] Remove release field, add preview1 identifier

[matschaffer]

What does this PR do?

Remove release field, add preview1 identifier

This is based on recommendations in elastic/kibana#122973 and elastic/package-spec#225

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.

Author's Checklist

• [ ]

How to test this PR locally

Related issues

Closes #4107

Screenshots

[matschaffer]

Wrong branch, closing.

[elasticmachine]

🚀 Benchmarks report

Package elasticsearch 👍(1) 💚(1) 💔(3)

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Data stream	Previous EPS	New EPS	Diff (%)	Result
audit	1506.02	1137.66	-368.36 (-24.46%)	💔
gc	9615.38	6250	-3365.38 (-35%)	💔
slowlog	3875.97	3144.65	-731.32 (-18.87%)	💔

Package kibana 👍(0) 💚(1) 💔(1)

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Data stream	Previous EPS	New EPS	Diff (%)	Result
audit	8771.93	5714.29	-3057.64 (-34.86%)	💔

To see the full report comment with /test benchmark fullreport

[elasticmachine]

💚 Build Succeeded

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Build stats

• Start Time: 2022-10-06T06:16:46.133+0000

• Duration: 15 min 46 sec

Test stats 🧪

Test	Results
Failed	0
Passed	82
Skipped	0
Total	82

🤖 GitHub comments

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To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (9/9)	💚
Files	100.0% (19/19)	💚 2.73
Classes	100.0% (19/19)	💚 2.73
Methods	78.756% (152/193)	👎 -11.177
Lines	90.414% (830/918)	👎 -1.232
Conditionals	100.0% (0/0)	💚