Regenerate moz.build files for the special handling in gn_processor.py
for gbm, drm and PipeWire libraries and for updates in GN config files.
Generation command:
./mach python build/gn_processor.py \
dom/media/webrtc/third_party_build/gn-configs/webrtc.json
Differential Revision: https://phabricator.services.mozilla.com/D242279