[+DOC] Restore policies in restoring ILM indices (#90119)

* [+DOC] Restore policies in restoring ILM indices

👋 howdy! This may need Asciidoc reformatting. Will you kindly add in express commentary on [Restore a managed Datastream or Index](https://www.elastic.co/guide/en/elasticsearch/reference/master/index-lifecycle-and-snapshots.html?edit) to also restore ILM policies as needed (via `include_global_state`). Otherwise, you induce ILM errors once ILM starts (and have to do a form of repeating the entire outlined procedure to get indices going through correctly.)

* Apply suggestions from code review

Co-authored-by: Abdon Pijpelink <abdon.pijpelink@elastic.co>

Co-authored-by: Abdon Pijpelink <abdon.pijpelink@elastic.co>
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

docs/reference/ilm/ilm-and-snapshots.asciidoc

@@ -2,6 +2,11 @@
 [[index-lifecycle-and-snapshots]]
 == Restore a managed data stream or index
 
+To <<restore-snapshot-api,restore>> managed indices, ensure that the {ilm-init}
+policies referenced by the indices exist. If necessary, you can restore
+{ilm-init} policies by setting
+<<restore-snapshot-api-request-body,`include_global_state`>> to `true`. 
+
 When you restore a managed index or a data stream with managed backing indices, 
 {ilm-init} automatically resumes executing the restored indices' policies.
 A restored index's `min_age` is relative to when it was originally created or rolled over,