Fix typo with stage name in iam roles (opensearch-project#10329)

Signed-off-by: Andre Kurait <[email protected]>

Author: AndreKurait

_migration-assistant/deploying-migration-assistant/iam-and-security-groups-for-existing-clusters.md

@@ -32,13 +32,13 @@ When migrating between two managed clusters, for example, when both domains were
 Use the following steps to grant the required permissions:
 
 1. In the AWS Management Console, navigate to **CloudFormation** > **Stacks**.
-2. Locate the stack that starts with `OSMigrations-<state>-<region>` (created during CDK deployment).
+2. Locate the stack that starts with `OSMigrations-<stage>-<region>` (created during CDK deployment).
 3. Go to the **Resources** tab and locate the following IAM roles:
 
    ```bash
-   arn:aws:iam::****:role/OSMigrations-<state>-<region>-MigrationServiceTaskRoleC-
-   arn:aws:iam::****:role/OSMigrations-<state>-<region>-reindexfromsnapshotTaskRo-
-   arn:aws:iam::****:role/OSMigrations-<state>-<region>-trafficreplayerdefaultTas-
+   arn:aws:iam::****:role/OSMigrations-<stage>-<region>-MigrationServiceTaskRoleC-
+   arn:aws:iam::****:role/OSMigrations-<stage>-<region>-reindexfromsnapshotTaskRo-
+   arn:aws:iam::****:role/OSMigrations-<stage>-<region>-trafficreplayerdefaultTas-
    ```
 
 4. In both the source and target clusters, map users to each Amazon Resource Name (ARN) using the following steps: