Enable the full OpenTelemetry in BigQuery Agent Analytics

compare the schema in cloud tracing and https://docs.cloud.google.com/stackdriver/docs/reference/telemetry/trace-schema and bigquery agent analytics https://adk.dev/integrations/bigquery-agent-analytics/ , 1, draft a detailed schema compare doc , focus on the schema alignment and difference for two span storage formats. Add the plan can make the BigQuery Agent Analytics can fully leverage opentelemetry and also how to make the BQ AA SDK can fully support the trace data from cloud trace format