NdkMediaExtractor: per-sample format metadata API

Bug: 63934228
Test: MediaPlayer2Test
Change-Id: I8ac081ba91152b1bb2e7bb61bf6977f90bcb8e3c
diff --git a/media/libmediaplayer2/nuplayer2/NuPlayer2.cpp b/media/libmediaplayer2/nuplayer2/NuPlayer2.cpp
index 5971a8b..060b698 100644
--- a/media/libmediaplayer2/nuplayer2/NuPlayer2.cpp
+++ b/media/libmediaplayer2/nuplayer2/NuPlayer2.cpp
@@ -2842,7 +2842,7 @@
 void NuPlayer2::sendSubtitleData(const sp<ABuffer> &buffer, int32_t baseIndex) {
     int32_t trackIndex;
     int64_t timeUs, durationUs;
-    CHECK(buffer->meta()->findInt32("trackIndex", &trackIndex));
+    CHECK(buffer->meta()->findInt32(AMEDIAFORMAT_KEY_TRACK_INDEX, &trackIndex));
     CHECK(buffer->meta()->findInt64("timeUs", &timeUs));
     CHECK(buffer->meta()->findInt64("durationUs", &durationUs));