Add fuzzer for TURN unwrap.

This is called on received network packets if dump_rtp_packets_ is on.

NOTRY=true

Review-Url: https://codereview.webrtc.org/2126463002
Cr-Original-Commit-Position: refs/heads/master@{#13394}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 262ba77d78c2f2b718be6dab158afa69e9c7d5fe
2 files changed