Updating trunk VERSION from 4188.0 to 4189.0

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

Change-Id: I7ac05ad4e8817a78ca15f868ba9a113b3d457929
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2277443Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#784295}

chrome/VERSION

 MAJOR=86
 MINOR=0
-BUILD=4188
+BUILD=4189
 PATCH=0