Only attempt to rollover signals index if version < builtin version (#84982) (#84996)

Author: marshallmain

x-pack/plugins/security_solution/server/lib/detection_engine/routes/index/create_index_route.ts

@@ -78,7 +78,7 @@ export const createDetectionIndex = async (
   const indexExists = await getIndexExists(callCluster, index);
   if (indexExists) {
     const indexVersion = await getIndexVersion(callCluster, index);
-    if (indexVersion !== SIGNALS_TEMPLATE_VERSION) {
+    if ((indexVersion ?? 0) < SIGNALS_TEMPLATE_VERSION) {
       await callCluster('indices.rollover', { alias: index });
     }
   } else {

x-pack/plugins/security_solution/server/lib/detection_engine/routes/index/read_index_route.ts

@@ -38,7 +38,7 @@ export const readIndexRoute = (router: IRouter) => {
           let mappingOutdated: boolean | null = null;
           try {
             const indexVersion = await getIndexVersion(clusterClient.callAsCurrentUser, index);
-            mappingOutdated = indexVersion !== SIGNALS_TEMPLATE_VERSION;
+            mappingOutdated = (indexVersion ?? 0) < SIGNALS_TEMPLATE_VERSION;
           } catch (err) {
             const error = transformError(err);
             // Some users may not have the view_index_metadata permission necessary to check the index mapping version