[AO] Only access the title for a data view using `getIndexPattern` method

[simianhacker]

We need to update the following files to stop accessing the title attribute directly:

• https://github.com/elastic/kibana/tree/main/x-pack/plugins/observability/public/components/threshold/hooks/use_metrics_explorer_data.ts#:~:text=title
• https://github.com/elastic/kibana/tree/main/x-pack/plugins/observability/public/components/threshold/threshold_rule_expression.tsx#:~:text=title
• https://github.com/elastic/kibana/tree/main/x-pack/plugins/observability/public/components/threshold/components/alert_details_app_section.tsx#:~:text=title

[elasticmachine]

Pinging @elastic/actionable-observability (Team: Actionable Observability)

[maryam-saeidi]

@simianhacker What is the difference between using getIndexPattern and directly accessing the title?

[simianhacker]

@maryam-saeidi They are essentially the same thing... title is set to whatever you have chosen for the index pattern. For example, if I was creating a new DataView called Metricbeat Indices and I set the index pattern to metricbeat-*, the title attribute would be metricbeat-* and the name would be Metricbeat Indices. I believe the Kibana team is trying to undo this by depreciating accessing these "legacy" fields directly and moving people to use the accessor methods like getindexPattern or getName.

[elasticmachine]

Pinging @elastic/obs-ux-management-team (Team:obs-ux-management)

[maryam-saeidi]

@mgiota Are you working on this issue, or shall we remove you from assignees?