### Elasticsearch Version

All

### Installed Plugins

N/A

### Java Version

_bundled_

### OS Version

N/A

### Problem Description

Today if an index has an `index.auto_expand_replicas` setting which cannot be realised in the cluster then the number of replicas is left unchanged by `AllocationService#adaptAutoExpandReplicas()`. Instead, I think we should change the number of replicas to the closest value within the permitted range.

For instance: if a cluster has a single data node which is marked as shutting down for restart then auto-expand replicas considers this cluster to have zero data nodes, and hence requires -1 replicas. If an index is created with `index.auto_expand_replicas: "0-1"` then it will not be adjusted to have zero replicas, even though this would be better than leaving it at the default value of 1 replica, and will ultimately be the correct setting.

### Steps to Reproduce

1. Create a cluster with one data node.
2. Put a `RESTART` shutdown marker on the data node.
3. Create an index with `index.auto_expand_replicas: "0-1"`
4. Observe that this results in an unassigned replica.

### Logs (if relevant)

_No response_
server/src/test/java/org/elasticsearch/cluster/metadata/AutoExpandReplicasTests.java
n.getName(),
                            n.getId(),
                            buildNewFakeTransportAddress(),
                            n.getAttributes(),
                            n.getRoles(),
                            n.getVersion()
                        )
                    )
                    .collect(Collectors.toCollection(ArrayList::new));
                if (randomBoolean()) {
                    nodesToAdd.add(createNode(DiscoveryNodeRole.DATA_ROLE));
                }
                state = cluster.joinNodesAndBecomeMaster(state, nodesToAdd);
                postTable = state.routingTable().index("index").shard(0);
            }
            Set<String> unchangedAllocationIds = RoutingNodesHelper.asStream(preTable)
                .filter(shr -> unchangedNodeIds.contains(shr.currentNodeId()))
                .map(shr -> shr.allocationId().getId())
                .collect(Collectors.toSet());
            assertThat(postTable.toString(), unchangedAllocationIds, everyItem(is(in(postTable.getAllAllocationIds()))));
            RoutingNodesHelper.asStream(postTable).forEach(shardRouting -> {
                if (shardRouting.assignedToNode() && unchangedAllocationIds.contains(shardRouting.allocationId().getId())) {
                    assertTrue("Shard should be active: " + shardRouting, shardRouting.active());
                }
            });
        } finally {
            terminate(threadPool);
        }
    }
    public void testOnlyAutoExpandAllocationFilteringAfterAllNodesUpgraded() {