Creates or updates a policy assignment.

This operation creates or updates the policy assignment with the given ID. Policy assignments made on a scope apply to all resources contained in that scope. For example, when you assign a policy to a resource group that policy applies to all resources in the group. Policy assignment IDs have this format: '{scope}/providers/Microsoft.Authorization/policyAssignments/{policyAssignmentName}'. Valid scopes are: management group (format: '/providers/Microsoft.Management/managementGroups/{managementGroup}'), subscription (format: '/subscriptions/{subscriptionId}'), resource group (format: '/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}', or resource (format: '/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{resourceProviderNamespace}/[{parentResourcePath}/]{resourceType}/{resourceName}'.