Updating trunk VERSION from 4206.0 to 4207.0

# This is an automated release commit.
# Do not revert without consulting chrome-pmo@google.com.
NOAUTOREVERT=true
TBR=kariah@chromium.org

Change-Id: I6bbc5596eda5fed4b9a49eaa4b767fbf2bd7bd5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2305750Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#789740}

chrome/VERSION

 MAJOR=86
 MINOR=0
-BUILD=4206
+BUILD=4207
 PATCH=0