Updating trunk VERSION from 3637.0 to 3638.0

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

Change-Id: I3a2c55aac4b8ed8000550c8093cc96139918deab
Reviewed-on: https://chromium-review.googlesource.com/c/1371127Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615422}

chrome/VERSION

 MAJOR=73
 MINOR=0
-BUILD=3637
+BUILD=3638
 PATCH=0