Check AudioDecoderConfig description for FLAC and Vorbis
By FLAC and Vorbis specs for WebCodecs [1, 2], the description data in
their AudioDecoderConfigs are required. Previously, no check for
description data is in WebCodecs code. This patch ensures that the
description is present for the FLAV and Vorbis codecs.
[1] https://www.w3.org/TR/webcodecs-flac-codec-registration/
[2] https://www.w3.org/TR/webcodecs-vorbis-codec-registration/
Differential Revision: https://phabricator.services.mozilla.com/D220205
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1915002
gecko-commit: 6ff3f1fba36ff308f3e534c7bcc1edf0dbdba956
gecko-reviewers: media-playback-reviewers, alwu