**Affected version:** 8.2 - 8.5.2
**Fixed in:** 8.5.3

### Problem Description

The problem applies to transforms that use more than 1 CCS cluster or 1 local and 1 CCS as source. A typical source could look like this (the important part: `remotes*`):

```
        "index" : [
          "remotes*:filebeat*"
        ],

```

If 2 indices share the same name the transform might fail with an error similar to this:

```
 Failed to retrieve checkpoint due to: Duplicate key logs-2022-11-14 (attempted merging values [... and ...]
```

Similar to the above the `_stats` call is broken for such a transform, it can fail with an error message starting with:

```
Failure during checkpoint retrieval
```

This can happen even if the transform is in state `STOPPED` or `FAILED`.

### Mitigation

Choose _one_ of the following mitigations:

 - split your transforms to use max 1 CCS/local indices

_or_

 - avoid upgrading to 8.2, until the issue got resolved (this is a regression of #80984)

_or_

 - avoid duplicate names for your indices even on remote cluster, e.g. name the index: `remote1-filebeat...`, `remote2-filebeat...`


### Solution

This is a regression of #80984 which introduced a new way of check-pointing. The remote needs to be prefixed to the index name.
x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/checkpoint/DefaultCheckpointProvider.java
final TransformConfigManager transformConfigManager,
        final TransformAuditor transformAuditor,
        final TransformConfig transformConfig
    ) {
        this.clock = clock;
        this.client = client;
        this.remoteClusterResolver = remoteClusterResolver;
        this.transformConfigManager = transformConfigManager;
        this.transformAuditor = transformAuditor;
        this.transformConfig = transformConfig;
    }
    @Override
    public void sourceHasChanged(final TransformCheckpoint lastCheckpoint, final ActionListener<Boolean> listener) {
        listener.onResponse(false);
    }
    @Override
    public void createNextCheckpoint(final TransformCheckpoint lastCheckpoint, final ActionListener<TransformCheckpoint> listener) {
        final long timestamp = clock.millis();
        final long checkpoint = TransformCheckpoint.isNullOrEmpty(lastCheckpoint) ? 1 : lastCheckpoint.getCheckpoint() + 1;
        getIndexCheckpoints(ActionListener.wrap(checkpointsByIndex -> {
            reportSourceIndexChanges(
                TransformCheckpoint.isNullOrEmpty(lastCheckpoint)
                    ? Collections.emptySet()
                    : lastCheckpoint.getIndicesCheckpoints().keySet(),
                checkpointsByIndex.keySet()
            );
            listener.onResponse(new TransformCheckpoint(transformConfig.getId(), timestamp, checkpoint, checkpointsByIndex, 0L));
        }, listener::onFailure));
    }
    protected void getIndexCheckpoints(ActionListener<Map<String, long[]>> listener) {