Use rtp_header_extension_map.h instead of rtp_header_extension.h

Finish renaming started in the https://chromium-review.googlesource.com/c/520947/

Bug: webrtc:5565
Change-Id: If420e05165ef7c110b7d38f53dbe73c21a4059bc
Reviewed-on: https://chromium-review.googlesource.com/528095
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Cr-Original-Commit-Position: refs/heads/master@{#18538}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 84b4d2c1c2db7f65c3d67238ce4af0042885ac97
7 files changed