Fix AAC audio failing to play due to FFmpegAllowLists

[rany2]

Chromium has the "aac" codec in the allow list, but we use libfdk-aac instead, which has a different codec name.

Fixes https://github.com/flathub/org.chromium.Chromium/issues/340

[flathubbot]

Started test build 87902

[flathubbot]

Build 87902 was cancelled

[flathubbot]

Started test build 87903

[flathubbot]

Build 87903 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/70569/com.github.Eloston.UngoogledChromium.flatpakref