Add app packages to all specified devices via DeviceQuery. This call can also be used to change the channel of an existing app. If the supplied channel is not available for the app the closest available channel will be used. For example if prod is specified but the app is only published to beta the beta channel will be selected. If the channel is not specified the best available channel will be selected, prod then beta then alpha. A DeviceQuery may contain one collection of deviceIds, serials, labelIds or deviceKeys. Schedule is optional.