Revert "Remove role mapping block check (#114223)"

This reverts commit ce07060.

Author: n1v0lg

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/authz/RoleMappingMetadata.java

@@ -12,6 +12,7 @@
 import org.elasticsearch.cluster.AbstractNamedDiffable;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.NamedDiff;
+import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.common.collect.Iterators;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -57,6 +58,7 @@ public final class RoleMappingMetadata extends AbstractNamedDiffable<Metadata.Cu
     private static final RoleMappingMetadata EMPTY = new RoleMappingMetadata(Set.of());
 
     public static RoleMappingMetadata getFromClusterState(ClusterState clusterState) {
+        clusterState.blocks().globalBlockedRaiseException(ClusterBlockLevel.READ);
         return clusterState.metadata().custom(RoleMappingMetadata.TYPE, RoleMappingMetadata.EMPTY);
     }