mediaextractor: load extractor plug-ins from apex

Note: media apex is not added in the default build.
The new code path will be no-op for now.

Test: boot & adb shell dumpsys media.extractor
Bug: 112766843
Change-Id: I1bdf2c41cc5f88c80c2fd20677dce1d58420e947
diff --git a/services/mediaextractor/MediaExtractorService.h b/services/mediaextractor/MediaExtractorService.h
index 9df3ecd..6007004 100644
--- a/services/mediaextractor/MediaExtractorService.h
+++ b/services/mediaextractor/MediaExtractorService.h
@@ -27,7 +27,7 @@
 {
     friend class BinderService<MediaExtractorService>;    // for MediaExtractorService()
 public:
-    MediaExtractorService() : BnMediaExtractorService() { }
+    MediaExtractorService();
     virtual ~MediaExtractorService() { }
     virtual void onFirstRef() { }