[Backport 2.x] Admin role for Query insights plugin (#4022)

Backport 6b9ded2 from #4006.

Signed-off-by: Chenyang Ji <cyji@amazon.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

config/roles.yml

@@ -398,3 +398,9 @@ flow_framework_read_access:
     - 'cluster:admin/opensearch/flow_framework/workflow_state/get'
     - 'cluster:admin/opensearch/flow_framework/workflow_state/search'
     - 'cluster:admin/opensearch/flow_framework/workflow_step/get'
+
+# Allows users to use all query insights APIs
+query_insights_full_access:
+  reserved: true
+  cluster_permissions:
+    - 'cluster:admin/opensearch/insights/top_queries/*'