Add --require-audio

By default, scrcpy mirrors only the video when audio capture fails on
the device. Add a flag to force scrcpy to fail if audio is enabled but
does not work.

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

app/src/options.c

@@ -72,6 +72,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .start_fps_counter = false,
     .power_on = true,
     .audio = true,
+    .require_audio = false,
     .list_encoders = false,
     .list_displays = false,
 };