extractor: load extractors on boot, not on request.

Test: build + dumpsys media.extractor
Bug: 131106476
Change-Id: Idbea788340c4849f1286727c159a8eb43d6a7bb0
diff --git a/services/mediaextractor/MediaExtractorService.cpp b/services/mediaextractor/MediaExtractorService.cpp
index de5c3e4..36e084b 100644
--- a/services/mediaextractor/MediaExtractorService.cpp
+++ b/services/mediaextractor/MediaExtractorService.cpp
@@ -30,7 +30,9 @@
 namespace android {
 
 MediaExtractorService::MediaExtractorService()
-        : BnMediaExtractorService() { }
+        : BnMediaExtractorService() {
+    MediaExtractorFactory::LoadExtractors();
+}
 
 sp<IMediaExtractor> MediaExtractorService::makeExtractor(
         const sp<IDataSource> &remoteSource, const char *mime) {