Incrementing VERSION to 90.0.4420.3

TBR=lakpamarthy@chromium.org

Change-Id: Id6475f1df9e3c908a00eca721af59c89bc9dec1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2713286
Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/4420@{#7}
Cr-Branched-From: 21135c1-refs/heads/master@{#854096}

chrome/VERSION

@@ -1,4 +1,4 @@
 MAJOR=90
 MINOR=0
 BUILD=4420
-PATCH=2
+PATCH=3