Fix test failures

Bug: 123077756
Test: CTS
Change-Id: I2b440fef382bd7a6b5d956defd7715ec614f8d31
diff --git a/include/media/MediaExtractorPluginHelper.h b/include/media/MediaExtractorPluginHelper.h
index f4d4da6..b86f177 100644
--- a/include/media/MediaExtractorPluginHelper.h
+++ b/include/media/MediaExtractorPluginHelper.h
@@ -171,6 +171,9 @@
 };
 
 inline CMediaTrack *wrap(MediaTrackHelper *track) {
+    if (track == nullptr) {
+        return nullptr;
+    }
     CMediaTrack *wrapper = (CMediaTrack*) malloc(sizeof(CMediaTrack));
     wrapper->data = track;
     wrapper->free = [](void *data) -> void {