[sentinel_one] Update README Instructions and Improve System Test Coverage

[mohitjha-elastic]

Proposed commit message

sentinel_one: update API token generation instructions in readme and improve system test coverage

Updated the README instructions for generating the API token, as the previous steps were based on an
older UI. Additionally, system test coverage for all data streams has been improved by including checks
ranging from Level 0, which verifies basic functionality, to Level 2, which ensures proper pagination.

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.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

How to test this PR locally

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

elastic-package test -v

Related Issue

• Closes Sentinel One: Improve system test coverage #15263
• Closes Sentinel One: Steps for generating token is outdated #15269

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[elastic-vault-github-plugin-prod]

🚀 Benchmarks report

To see the full report comment with /test benchmark fullreport

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: aa6ba1a

cc @mohitjha-elastic

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[efd6]

LGTM

suggest commit message body:

Updated README instructions for generating the API token, as the
previous steps were based on an older UI.

Additionally, system test coverage for all data streams has been
improved by including checks ranging from Level 0, which verifies basic
functionality, to Level 2, which ensures proper pagination.

[elastic-vault-github-plugin-prod]

Package sentinel_one - 1.39.0 containing this change is available at https://epr.elastic.co/package/sentinel_one/1.39.0/