Updating trunk VERSION from 4205.0 to 4206.0

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

Change-Id: Ia672fcc1b00bf20447673c3b4c206e0ec83e5af5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2303786Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#789344}

chrome/VERSION

 MAJOR=86
 MINOR=0
-BUILD=4205
+BUILD=4206
 PATCH=0