Two speedups to IndexNameExpressionResolver (#112486)

Two obvious speedups to the IndexNameExpressionResolver where we can
defer an expensive lookup from either the indices lookup or the thread
context to if and when we actually need it.

Author: original-brownbear

server/src/main/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolver.java

@@ -567,17 +567,14 @@ private static boolean shouldTrackConcreteIndex(Context context, IndicesOptions
             // Exclude this one as it's a net-new system index, and we explicitly don't want those.
             return false;
         }
-        if (DataStream.isFailureStoreFeatureFlagEnabled()) {
-            IndexAbstraction indexAbstraction = context.getState().metadata().getIndicesLookup().get(index.getName());
-            if (context.options.allowFailureIndices() == false) {
-                DataStream parentDataStream = indexAbstraction.getParentDataStream();
-                if (parentDataStream != null && parentDataStream.isFailureStoreEnabled()) {
-                    if (parentDataStream.isFailureStoreIndex(index.getName())) {
-                        if (options.ignoreUnavailable()) {
-                            return false;
-                        } else {
-                            throw new FailureIndexNotSupportedException(index);
-                        }
+        if (DataStream.isFailureStoreFeatureFlagEnabled() && context.options.allowFailureIndices() == false) {
+            DataStream parentDataStream = context.getState().metadata().getIndicesLookup().get(index.getName()).getParentDataStream();
+            if (parentDataStream != null && parentDataStream.isFailureStoreEnabled()) {
+                if (parentDataStream.isFailureStoreIndex(index.getName())) {
+                    if (options.ignoreUnavailable()) {
+                        return false;
+                    } else {
+                        throw new FailureIndexNotSupportedException(index);
                     }
                 }
             }

server/src/main/java/org/elasticsearch/indices/SystemIndices.java

@@ -562,11 +562,10 @@ public static SystemIndexAccessLevel getSystemIndexAccessLevel(ThreadContext thr
         // This method intentionally cannot return BACKWARDS_COMPATIBLE_ONLY - that access level should only be used manually
         // in known special cases.
         final String headerValue = threadContext.getHeader(SYSTEM_INDEX_ACCESS_CONTROL_HEADER_KEY);
-        final String productHeaderValue = threadContext.getHeader(EXTERNAL_SYSTEM_INDEX_ACCESS_CONTROL_HEADER_KEY);
 
         final boolean allowed = Booleans.parseBoolean(headerValue, true);
         if (allowed) {
-            if (productHeaderValue != null) {
+            if (threadContext.getHeader(EXTERNAL_SYSTEM_INDEX_ACCESS_CONTROL_HEADER_KEY) != null) {
                 return SystemIndexAccessLevel.RESTRICTED;
             } else {
                 return SystemIndexAccessLevel.ALL;