[Spring Boot] Update the field in audit_events data stream dashboard

[harnish-crest]

• Bug

What does this PR do?

This PR is of the Spring Boot integration to update the field name in audit_events data stream dashboard and some nits in fields descriptions. Along with the fixes, it also enhances the integration by following some of the best practices of integration development.

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.

How to test this PR locally

• Clone integrations repo.
• Install elastic-package locally.
• Start elastic stack using elastic-package.
• Move to integrations/packages/spring_boot directory.
• Run the following command to run tests.

elastic-package test

[elasticmachine]

💚 Build Succeeded

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Build stats

• Start Time: 2022-08-05T10:22:09.720+0000

• Duration: 19 min 40 sec

Test stats 🧪

Test	Results
Failed	0
Passed	36
Skipped	0
Total	36

🤖 GitHub comments

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

• /test : Re-trigger the build.

[yug-rajani]

/test

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (2/2)	💚
Files	100.0% (2/2)	💚 2.953
Classes	100.0% (2/2)	💚 2.953
Methods	100.0% (27/27)	💚 10.458
Lines	93.289% (139/149)	👍 1.808
Conditionals	100.0% (0/0)	💚

[yug-rajani]

/test

[yug-rajani]

/test

[kush-elastic]

LGTM