Added role authorization pre-req

Author: anosov1960

docs/sql-server/azure-arc/overview.md

@@ -56,6 +56,8 @@ To connect the SQL Server instances and the hosting machine to Azure Arc, you mu
 - Microsoft.HybridCompute/machines/read
 - Microsoft.HybridCompute/machines/write
 - Microsoft.GuestConfiguration/guestConfigurationAssignments/read
+- Microsoft.Authorization/roleAssignments/write
+- Microsoft.Authorization/roleAssignments/read
 
 For optimal security, create a custom role in Azure that has the minimal permissions listed. For information on how to create a custom role in Azure with these permissions, see [Custom roles overview](/azure/active-directory/users-groups-roles/roles-custom-overview). To add role assignment, see [Add or remove role assignments using Azure portal](/azure/role-based-access-control/role-assignments-portal) or [Add or remove role assignments using Azure RBAC and Azure CLI](/azure/role-based-access-control/role-assignments-cli).