We're trying to make the jump to Opus everywhere for Construct 3, so that you no longer need to worry about having multiple audio formats. We're having a few problems with decoding Opus on platforms that don't natively support it though, and Samsung Internet falsely claiming to support Opus natively is another issue. We're aware of these issues and hope to have them sorted out soon.
The runtime will pick any other natively supported audio file over Opus if there is one, so you should be able to import AAC and delete the Opus file and have correct audio playback work. The Samsung Internet browser says it can play AAC so that should work as a workaround - please file a bug report if it doesn't (but who knows, it already lies about Opus, maybe it lies about others...)