[Cloud Posture] convert score index to data stream

[CohenIdo]

Motivation As part of cloud posture plugin, we are using logs-cloud_security_posture.scores index as regular index (aka not a data stream) to write the current cluster score every 5 minutes. Due to the append-only nature of score indexes, I believe it is better to have the score index be a data stream. In addition, the current index is missing ILM policy, to smoothly support ILM is better to have data stream and not regular index.

** Before implementing, please read the following comment.

Definition of done

• [ ] Create score data stream via CSPM integration
• [ ] Delete index creation from Kibana
• [ ] Support ILM
• [ ] Udpate Elasticsearch privileges for kibana_system user

Out of scope

Related tasks/epics

• https://github.com/elastic/security-team/issues/4885

Checklist

Please follow the following checklist in the beginning of your work, please comment with a suggested of high level solution. It should include:

• [ ] Comment describing high level implementation details
  • [ ] Include API and data models
  • [ ] Include assumptions being taken
  • [ ] Provide backward/forward compatibility when changing data model schemas and key constants
  • [ ] Mention relevant individuals with a reason (getting feedback, fyi etc)
• [ ] Submit a PR for our technical index that includes breaking changes/ new features

Before closing this ticket

• [ ] Commit the technical index PR
• [ ] Reference to tech-debts that shall be solved as we move forward

[elasticmachine]

Pinging @elastic/kibana-cloud-security-posture (Team:Cloud Security Posture)