Use zero offset when delegating EMSG sample data

When delegating EMSG samples in `HlsSampleStreamWrapper`,
the offset passed into `sampleMetadata(..)` of the delegate
`TrackOutput` must be zero because it is called immediately
after `sampleData(..)` is called.

The condition to trigger this issue is that more than one
metadata samples are pending in `pendingMetadataSampleInfos`
of `FragmentedMp4Extractor` which produces non-zero offsets.

Issue: #1002
Issue: #1203
PiperOrigin-RevId: 623210835

RELEASENOTES.md

@@ -25,6 +25,10 @@
 *   Cronet Extension:
 *   RTMP Extension:
 *   HLS Extension:
+    *   Fix bug where pending EMSG samples waiting for a discontinuity were
+        delegated in `HlsSampleStreamWrapper` with an incorrect offset causing
+        an `IndexOutOfBoundsException` or an `IllegalArgumentException`
+        ([#1002](https://github.com/androidx/media/issues/1002)).
 *   DASH Extension:
 *   Smooth Streaming Extension:
 *   RTSP Extension:

libraries/exoplayer_hls/src/main/java/androidx/media3/exoplayer/hls/HlsSampleStreamWrapper.java

@@ -1882,7 +1882,7 @@ public void sampleMetadata(
       int sampleSize = sampleForDelegate.bytesLeft();
 
       delegate.sampleData(sampleForDelegate, sampleSize);
-      delegate.sampleMetadata(timeUs, flags, sampleSize, offset, cryptoData);
+      delegate.sampleMetadata(timeUs, flags, sampleSize, /* offset= */ 0, cryptoData);
     }
 
     private boolean emsgContainsExpectedWrappedFormat(EventMessage emsg) {