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
task.request.waitForActiveShards(),
                                task.request.ackTimeout(),
                                shardsAcknowledged -> {
                                    if (shardsAcknowledged == false) {
                                        logger.debug(
                                            "[{}] indices closed, but the operation timed out while "
                                                + "waiting for enough shards to be started.",
                                            Arrays.toString(waitForIndices)
                                        );
                                    }
                                    
                                    
                                    
                                    boolean shardsAcked = acknowledged ? shardsAcknowledged : false;
                                    task.listener().onResponse(new CloseIndexResponse(acknowledged, shardsAcked, indices));
                                },
                                task.listener()::onFailure
                            );
                        } else {
                            task.listener().onResponse(new CloseIndexResponse(acknowledged, false, indices));
                        }
                    });
                } catch (Exception e) {
                    taskContext.onFailure(e);
                }
            }
            return allocationService.reroute(state, "indices closed");
        }
    }
    private record CloseIndicesTask(