LibMedia: Initialize Track's primitive fields to zero

Author: https://github.com/Zaggy1024
Commit: ee3c080fb5
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6078
Reviewed-by: https://github.com/trflynn89 ✅

Libraries/LibMedia/Track.h

@@ -68,8 +68,8 @@ public:
     }
 
 private:
-    TrackType m_type;
+    TrackType m_type { 0 };
-    size_t m_identifier;
+    size_t m_identifier { 0 };
 
     Variant<Empty, VideoData> m_track_data;
 };