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
blockingResults.put(
                        result.getKey(),
                        new AddBlockResult(
                            result.getKey(),
                            new IllegalStateException(
                                "verification of shards before blocking " + index + " succeeded but block has been removed in the meantime"
                            )
                        )
                    );
                    logger.debug("verification of shards before blocking {} succeeded but block has been removed in the meantime", index);
                    continue;
                }
                assert currentBlock != null && currentBlock.equals(tempBlock) && currentBlock.id() == block.block.id();
                blocks.removeIndexBlockWithId(index.getName(), tempBlock.id());
                blocks.addIndexBlock(index.getName(), block.block);
                logger.debug("add block {} to index {} succeeded", block.block, index);
                effectivelyBlockedIndices.add(index.getName());
            } catch (final IndexNotFoundException e) {
                logger.debug("index {} has been deleted since blocking it started, ignoring", index);
            }
        }
        logger.info("completed adding block {} to indices {}", block.name, effectivelyBlockedIndices);
        return Tuple.tuple(ClusterState.builder(currentState).blocks(blocks).build(), List.copyOf(blockingResults.values()));
    }
    /**
     * @return Generates a {@link ClusterBlock} that blocks read and write operations on soon-to-be-closed indices. The
     * cluster block is generated with the id value equals to {@link #INDEX_CLOSED_BLOCK_ID} and a unique UUID.
     */
    public static ClusterBlock createIndexClosingBlock() {
        return new ClusterBlock(