Fix pool types

Author: nicktindall

server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java

@@ -185,12 +185,12 @@ public static ThreadPoolType fromType(String type) {
     }
 
     public static final Map<String, ThreadPoolType> THREAD_POOL_TYPES = Map.ofEntries(
-        entry(Names.GENERIC, ThreadPoolType.SCALING),
+        entry(Names.GENERIC, ThreadPoolType.VIRTUAL),
         entry(Names.CLUSTER_COORDINATION, ThreadPoolType.FIXED),
         entry(Names.GET, ThreadPoolType.FIXED),
         entry(Names.ANALYZE, ThreadPoolType.FIXED),
-        entry(Names.WRITE, ThreadPoolType.FIXED),
-        entry(Names.WRITE_COORDINATION, ThreadPoolType.FIXED),
+        entry(Names.WRITE, ThreadPoolType.VIRTUAL),
+        entry(Names.WRITE_COORDINATION, ThreadPoolType.VIRTUAL),
         entry(Names.SEARCH, ThreadPoolType.FIXED),
         entry(Names.SEARCH_COORDINATION, ThreadPoolType.FIXED),
         entry(Names.AUTO_COMPLETE, ThreadPoolType.FIXED),