A preview call can be quite expensive and cause timeout in a cluster. As a short term fix we identified 2 (hopefully) small fixes:

- make the call cancellable, the main issue here seems to be that preview calls search without using a parent task id(see this fix for data feeds: https://github.com/elastic/elasticsearch/pull/88142/files#diff-aba58244cb8f9dfa3ac3b6efeb02259e3d5956576f56c1ff5e243dd2aac27381)
- pass the timeout parameter of the preview call to the search call, currently a timeout can be specified, but is ignored for the inner search call, which is executed with no timeout (see https://www.elastic.co/guide/en/elasticsearch/reference/master/search-search.html#search-search-api-query-params).

Both changes are bugs and shall be relatively simple to implement and considered for backport to the 7.17 branch.

@przemekwitek can you have a look at this?

related: #88010
x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/action/TransportPreviewTransformAction.java
);
        
        ActionListener<Boolean> validateSourceDestListener = ActionListener.wrap(
            validateSourceDestResponse -> function.validateConfig(validateConfigListener),
            listener::onFailure
        );
        
        ActionListener<Void> checkPrivilegesListener = ActionListener.wrap(
            aVoid -> sourceDestValidator.validate(
                clusterState,
                config.getSource().getIndex(),
                config.getDestination().getIndex(),
                config.getDestination().getPipeline(),
                SourceDestValidations.getValidationsForPreview(config.getAdditionalSourceDestValidations()),
                validateSourceDestListener
            ),
            listener::onFailure
        );
        
        if (XPackSettings.SECURITY_ENABLED.get(nodeSettings)) {
            TransformPrivilegeChecker.checkPrivileges(
                "preview",
                securityContext,
                indexNameExpressionResolver,
                clusterState,
                client,
                config,
                
                
                DUMMY_DEST_INDEX_FOR_PREVIEW.equals(config.getDestination().getIndex()) == false,