Global AS override for auto-derived route targets in EVPN

EVPN now supports global autonomous system (AS) override for auto-derived route targets. You can configure independent AS control for import and export route target generation by using the import-as and export-as statements. Alternatively, you can configure unified AS control for both import and export route target generation by using the as-num statement. This feature provides additional control over the AS value used for EVPN auto-derived route target generation in multi-AS deployments.