HBASE-28391 Remove the need for ADMIN permissions for listDecommissionedRegionServers (#5695)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
index 66a7b3a..563470f 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
@@ -1206,7 +1206,7 @@
   @Override
   public void preListDecommissionedRegionServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
     throws IOException {
-    requirePermission(ctx, "listDecommissionedRegionServers", Action.ADMIN);
+    requirePermission(ctx, "listDecommissionedRegionServers", Action.READ);
   }
 
   @Override