Add --audio-codec

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

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

app/src/server.c

@@ -165,6 +165,8 @@ sc_server_get_codec_name(enum sc_codec codec) {
             return "h265";
         case SC_CODEC_AV1:
             return "av1";
+        case SC_CODEC_OPUS:
+            return "opus";
         default:
             return NULL;
     }
@@ -228,6 +230,10 @@ execute_server(struct sc_server *server,
         ADD_PARAM("video_codec=%s",
                   sc_server_get_codec_name(params->video_codec));
     }
+    if (params->audio_codec != SC_CODEC_OPUS) {
+        ADD_PARAM("audio_codec=%s",
+            sc_server_get_codec_name(params->audio_codec));
+    }
     if (params->max_size) {
         ADD_PARAM("max_size=%" PRIu16, params->max_size);
     }