Use /api/observability/notebooks/savedNotebook for list notebooks route (opensearch-project#666)

Signed-off-by: Craig Perkins <cwperx@amazon.com>

Author: cwperks

public/components/report_definitions/report_settings/report_settings.tsx

@@ -684,7 +684,7 @@ export function ReportSettings(props: ReportSettingProps) {
       });
 
     await httpClientProps
-      .get('../api/observability/notebooks/')
+      .get('../api/observability/notebooks/savedNotebook')
       .catch((error: any) => {
         console.error(
           'error fetching notebooks, retrying with legacy api',