Constant fidl_fuchsia_audio_device::DEFAULT_RING_BUFFER_ELEMENT_ID

pub const DEFAULT_RING_BUFFER_ELEMENT_ID: u64 = 0;

For devices with Dai or StreamConfig drivers, there is only one RING_BUFFER entity. When a method requires us to address the RingBuffer by ID, we use element_id 0. Dai and StreamConfig drivers that implement signalprocessing should not assign this ID to other elements.