If set, the SDK will be notified that the receiver application is
configured to support an interactive UI. This allows the receiver to
modify the UI ControlsSlot assignments and shows a transparent scrim over
the content when presented. If disabled, the ControlsSlots are not
configurable and the scrim presented is opaque. When playing audio
content the default UI will replace any custom UI. This flag is set by
default when using the cast-media-player element. For non-interactive
devices this flag has no effect. For these devices if using the
cast-media-player element, the SDK will render default UI. If using a
custom media element the SDK will rely on the receiver application to
define the UI components.