MPEG4Extractor:don't set delay and padding from 2nd edit list entry

media time and segment duration entries from 1st edit list entry only is
used for gapless playback, hence don't process the same from second edit
list entry.

Bug: 152372048

Test: atest android.media.cts.MediaMetadataRetrieverTest
      atest android.media.cts.MediaMuxerTest
      atest android.media.cts.MediaExtractorTest
      Gapless playback files played as expected.
Change-Id: I79ce7c69c65f71440e0ba6552e150586fab64aac