This will allow to create an AudioConfig with an unknown or unsupported channel layout, defaulting instead to the number of channels.
MozReview-Commit-ID: IonLuo9q2a5
If a channel layout is unsupported, the AudioConverter will instead just use the channel count information to leave the data as-is, only trimming extra channels, or inserting silence if needed.
MozReview-Commit-ID: CXOjcSRsRwI
Instead we place it at 32.
Future changes will change the meaning of this limit to when we can deal with channel layout. If outside that limit the audio will be played on a best attempt basis.
MozReview-Commit-ID: EavmmcxjLI0
That ChannelLayout uses an AutoTArray internally makes XPCOM report them as leaking when declared as static.
They weren't use outside of ChannelLayout anyway so they can be removed.
MozReview-Commit-ID: KVqdjzvL8pr