HLS: do not discard packets when queuing explicit discontinuity

in case of explicit discontinuity (#EXT-X-DISCONTINUITY tag in the
playlist), do not discard packets that's already queued.

(when seeking, the old fetcher will be discarded so this won't affect
seeking case.)

Bug: 15020526
Change-Id: I5d3fc489df35e3bc44acb1ee7851571cb99cb56b
diff --git a/media/libmediaplayerservice/nuplayer/RTSPSource.cpp b/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
index 94800ba..2338b23 100644
--- a/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
@@ -505,7 +505,10 @@
             TrackInfo *info = &mTracks.editItemAt(trackIndex);
             sp<AnotherPacketSource> source = info->mSource;
             if (source != NULL) {
-                source->queueDiscontinuity(ATSParser::DISCONTINUITY_SEEK, NULL);
+                source->queueDiscontinuity(
+                        ATSParser::DISCONTINUITY_SEEK,
+                        NULL,
+                        true /* discard */);
             }
 
             break;