And drop a few unneeded includes of rtc_base/stringencode.h.
Bug: webrtc:6424
Change-Id: I8be92a2ca199afaae1d3a177c23acbf2b9bdc465
Reviewed-on: https://webrtc-review.googlesource.com/c/105002
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25125}