[BUG] Agent Observability Dashboard: Missing index-pattern-fields for GenAI attributes

Description:

Multiple panels in the "Agent Observability" dashboard are failing to load data because the required index pattern fields cannot be located. The dashboard appears to be looking for OpenTelemetry GenAI semantic convention attributes that are either not indexed or mapped incorrectly in the default logs-otel-v1* pattern.

Panels Affected:

• Request Model (attributes.gen_ai.request.model)
• Tool Name (attributes.gen_ai.tool.name)
• Input Tokens (attributes.gen_ai.usage.input_tokens)
• Operation Name (attributes.gen_ai.operation.name)

Steps to reproduce:

Open Dashboards -> Observability -> Dashboards.
Select the Agent Observability dashboard.
Observe the error: Could not locate that index-pattern-field (id: ...) on at least 4 visualization panels.

Expected behavior:

The dashboard should gracefully handle missing fields or provide a clear setup guide to ensure OTel GenAI attributes are correctly mapped as keywords or long values during ingestion.

Start by opening Dashboards → Observability → Dashboards and reproducing the Agent Observability failure. Inspect how the default logs-otel-v1* pattern is used for the four listed GenAI fields, then determine whether missing fields should be handled gracefully or documented with setup guidance. Done means the affected panels no longer fail without a clear resolution path.