add search model group permission to ml_read_access role (opensearch-project#2855)

* add search model group permission to ml_read_access role

Signed-off-by: Bhavana Ramaram <rbhavna@amazon.com>
Signed-off-by: Sam <samuel.costa@eliatra.com>

Author: rbhavna

config/roles.yml

@@ -258,6 +258,7 @@ ml_read_access:
   reserved: true
   cluster_permissions:
     - 'cluster:admin/opensearch/ml/stats/nodes'
+    - 'cluster:admin/opensearch/ml/model_groups/search'
     - 'cluster:admin/opensearch/ml/models/get'
     - 'cluster:admin/opensearch/ml/models/search'
     - 'cluster:admin/opensearch/ml/tasks/get'