Address review comments

src/core/settings.h

@@ -26,6 +26,12 @@ enum class LayoutOption {
     SideScreen,
 };
 
+enum class MicInputType {
+    None,
+    Real,
+    Static,
+};
+
 namespace NativeButton {
 enum Values {
     A,
@@ -167,7 +173,7 @@ struct Values {
     bool enable_audio_stretching;
     std::string audio_device_id;
     float volume;
-    u8 mic_input_type;
+    MicInputType mic_input_type;
     std::string mic_input_device;
 
     // Camera