NuPlayer: add missing getSelectedTrack in CCDecoder

Test: cts
Bug: 119938763
Change-Id: I0dcc35ec65f0912d43aa5b0e3a797334d2581a78
diff --git a/media/libmediaplayer2/nuplayer2/NuPlayer2CCDecoder.cpp b/media/libmediaplayer2/nuplayer2/NuPlayer2CCDecoder.cpp
index e215965..a9f2104 100644
--- a/media/libmediaplayer2/nuplayer2/NuPlayer2CCDecoder.cpp
+++ b/media/libmediaplayer2/nuplayer2/NuPlayer2CCDecoder.cpp
@@ -199,6 +199,18 @@
     return OK;
 }
 
+ssize_t NuPlayer2::CCDecoder::getSelectedTrack(media_track_type type) const {
+    if (mSelectedTrack != -1) {
+        CCTrack track = mTracks[mSelectedTrack];
+        if (track.mTrackType == kTrackTypeCEA608 || track.mTrackType == kTrackTypeCEA708) {
+            return (type == MEDIA_TRACK_TYPE_SUBTITLE ? mSelectedTrack : -1);
+        }
+        return (type == MEDIA_TRACK_TYPE_UNKNOWN ? mSelectedTrack : -1);
+    }
+
+    return -1;
+}
+
 bool NuPlayer2::CCDecoder::isSelected() const {
     return mSelectedTrack >= 0 && mSelectedTrack < (int32_t)getTrackCount();
 }