Associate client devices with the provided core.

Associates 1 or more client devices with an existing Greengrass V2 core. If the referenced thingName does not exist, an AWS IoT Thing is provisioned using the provided provisioningTemplate. The AWS IoT thing is then associated with the Greengrass V2 core. This is an asynchronous call, meaning that when submitted the call will return immediately with a taskId while the cores are being created in the background. Use the GET /deviceTasks/{taskId} to retrieve the status of the task.