Add overlay for simplified Duration data type (#5407)

(cherry picked from commit 1c92db2)

Author: lcawl

docs/overlays/elasticsearch-shared-overlays.yaml

@@ -1151,3 +1151,11 @@ actions:
   - target: "$.components['schemas']['cat._types.CatTransformColumn'].enum"
     description: Remove enum array from cat transforms
     remove: true
+# Simplify duration type
+  - target: "$.components['schemas']['_types.Duration'].oneOf"
+    description: Remove existing oneOf definition for Duration
+    remove: true
+  - target: "$.components['schemas']['_types.Duration']"
+    description: Re-add a simple string type for Duration
+    update:
+      type: string