[NORMATIVE] Remove redundant byte from bitstream

Prior to this patch, an extra zero byte was being included in the
bitstream in order to emulate the termination of the entropy coder.
However, that version of the entropy coder was removed in commit
476c63c. In this patch we remove the redundant zero byte completely.

BUG=aomedia:1579

Change-Id: I20eeda5096997d687f5a6300aa646943d2dab1d6

av1/decoder/decodeframe.c

diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index 80436e9..58853b8 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -2685,8 +2685,6 @@
     if (cm->seq_params.frame_id_numbers_present_flag) {
       int frame_id_length = cm->seq_params.frame_id_length;
       int display_frame_id = aom_rb_read_literal(rb, frame_id_length);
-      // Read and discard one byte
-      aom_rb_read_literal(rb, 8);
       /* Compare display_frame_id with ref_frame_id and check valid for
        * referencing */
       if (display_frame_id != cm->ref_frame_id[existing_frame_idx] ||

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 94fad31..bb316f2 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -2976,10 +2976,6 @@
       int frame_id_len = cm->seq_params.frame_id_length;
       int display_frame_id = cm->ref_frame_id[cpi->existing_fb_idx_to_show];
       aom_wb_write_literal(wb, display_frame_id, frame_id_len);
-      /* Add a zero byte to prevent emulation of superframe marker */
-      /* Same logic as when when terminating the entropy coder */
-      /* Consider to have this logic only one place */
-      aom_wb_write_literal(wb, 0, 8);
     }
 
 #if CONFIG_FILM_GRAIN && !CONFIG_FILM_GRAIN_SHOWEX