Telemetry schema needs to include key from functional test in reporting

[rshen91]

In PR #163354, we ran into CI failures for the serverless functional testx-pack/test_serverless/api_integration/test_suites/observability/telemetry/snapshot_telemetry.ts.

The PR skips the test causing this error in x-pack/test_serverless/api_integration/test_suites/common/reporting/download_csv_dashboard.ts as a workaround.

Can this key be added to the schema or have a way in the future for tests to update the schema in the snapshot_telemetry.ts test?
stack_stats.kibana.plugins.core.apiCalls.savedObjectsImport.compatibilityModeEnabled.no

That way when running node ./scripts/functional_tests.js --config=x-pack/test_serverless/api_integration/test_suites/search/config.ts --grep="CSV Generation from SearchSource: Dashboard|API Snapshot telemetry should pass the schema validation" it doesn't matter if download_csv_dashboard.ts executes first or snapshot_telemetry.ts.

Thanks!

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)