Add --audio-codec

Introduce the selection mechanism. Alternative codecs will be added
later.

PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>

app/data/zsh-completion/_scrcpy

@@ -10,6 +10,7 @@ local arguments
 arguments=(
     '--always-on-top[Make scrcpy window always on top \(above other windows\)]'
     '--audio-bit-rate=[Encode the audio at the given bit-rate]'
+    '--audio-codec=[Select the audio codec]:codec:(opus)'
     {-b,--video-bit-rate=}'[Encode the video at the given bit-rate]'
     '--crop=[\[width\:height\:x\:y\] Crop the device screen on the server]'
     {-d,--select-usb}'[Use USB device]'