Tiny supportability nit: today we emit these log messages when adding a write block to an index:

```
[2022-03-22T19:43:26,897][INFO ][o.e.c.m.MetadataIndexStateService] [node_t1] adding block write to indices [[test-blocks/eLkrYpm_S3WNemfWpXrhPA]]
[2022-03-22T19:43:26,933][INFO ][o.e.c.m.MetadataIndexStateService] [node_t1] completed adding block write to indices [test-blocks]
```

This is kind of confusing, a `block write` sounds like we're writing a block of data. It's not clear that `write` is variable (we also say `block read`) or the name of a block setting. I think we should word this as `adding [index.blocks.write] block to indices` instead.
server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexStateService.java
taskContext.onFailure(e);
                }
            }
            return state;
        }
    }
    private record FinalizeBlocksTask(
        AddIndexBlockClusterStateUpdateRequest request,
        Map<Index, ClusterBlock> blockedIndices,
        Map<Index, AddBlockResult> verifyResults,
        ActionListener<AddIndexBlockResponse> listener
    ) implements ClusterStateTaskListener {
        @Override
        public void onFailure(Exception e) {
            listener.onFailure(e);
        }
        @Override
        public void clusterStateProcessed(ClusterState oldState, ClusterState newState) {
            assert false : "not called";
        }
    }
    /**
     * Step 2 - Wait for indices to be ready for closing
     * <p>
     * This step iterates over the indices previously blocked and sends a {@link TransportVerifyShardBeforeCloseAction} to each shard. If
     * this action succeed then the shard is considered to be ready for closing. When all shards of a given index are ready for closing,
     * the index is considered ready to be closed.
     */
    private class WaitForClosedBlocksApplied extends ActionRunnable<Map<Index, IndexResult>> {
        private final Map<Index, ClusterBlock> blockedIndices;