Create 2.1 AAC when importing surround sound AAC

When importing surround sound tracks, either AC3 or DTS, Subler has the option to passthru this sound track and create a 2.1 sound track from it. However, this doesn't work if the surround sound track already AAC. This is common with HEVC files. Many contain 6 Channel AAC.

Please update the preferences to allow creating 2.1 audio from any surround sound source, including AAC.