GCAdapter: Automatically start and stop thread

This keeps the logic encapsulated inside GCAdapter.cpp so callers don't
have to think about it.

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/NativeLibrary.kt

@@ -300,9 +300,6 @@ object NativeLibrary {
     @JvmStatic
     external fun ResetDolphinSettings()
 
-    @JvmStatic
-    external fun UpdateGCAdapterScanThread()
-
     /**
      * Initializes the native parts of the app.
      *

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/model/Settings.kt

@@ -56,7 +56,6 @@ class Settings : Closeable {
             NativeConfig.save(NativeConfig.LAYER_BASE)
 
             NativeLibrary.ReloadLoggerConfig()
-            NativeLibrary.UpdateGCAdapterScanThread()
         } else {
             NativeConfig.save(NativeConfig.LAYER_LOCAL_GAME)
         }