By default, for devices with larger amounts of outputs, CoreAudio can
provide invalid channel labels/positions, simply by starting at 0 and
incrementing forward. For example, values 19 through 32 are not valid
according to the CoreAudioBaseTypes.h header, but if your device has >19
output channels, you will find CoreAudio using those values.
This is most likely a bug in CoreAudio, since in that case it should use
unpositioned labels (e.g. _Discrete_X) instead.
This commit aims to work around this by overriding all channels to be
unpositioned if the case above is detected.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8311>
c5c5327df6