av1_dec_fuzzer: Initialize stream_info.is_annexb

The is_annexb member of aom_codec_stream_info_t must be properly
initialized.

Related to the libvpx CL
https://chromium-review.googlesource.com/c/webm/libvpx/+/5533523.

Bug: oss-fuzz:68930
Change-Id: I324d02ff1fd16541700ca5ecdb515e842e52bade

examples/av1_dec_fuzzer.cc

diff --git a/examples/av1_dec_fuzzer.cc b/examples/av1_dec_fuzzer.cc
index 6f3305e..4634ca6 100644
--- a/examples/av1_dec_fuzzer.cc
+++ b/examples/av1_dec_fuzzer.cc
@@ -68,6 +68,7 @@
     frame_size = std::min(size, frame_size);
 
     aom_codec_stream_info_t stream_info;
+    stream_info.is_annexb = is_annexb;
     aom_codec_err_t err =
         aom_codec_peek_stream_info(codec_interface, data, size, &stream_info);
     static_cast<void>(err);