[chromedriver] Add release script linux check

strip is incompatible on Mac with Linux, which could cause
large binary size. Make sure it's linux env before running
release script

Bug: chromedriver:3556
Change-Id: I7f7d9b9a12bb78a558016a28a7c5ecc3dc7098de
Notry: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2321715Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Auto-Submit: Shengfa Lin <shengfa@google.com>
Cr-Commit-Position: refs/heads/master@{#792114}

chrome/test/chromedriver/support/release/release.sh

@@ -6,6 +6,12 @@
 # Script to release ChromeDriver, by copying it from chrome-unsigned bucket to
 # chromedriver bucket.
 
+if [[ $(uname -s) != Linux* ]]
+then
+  echo Please run release.sh on Linux
+  exit 1
+fi
+
 if [[ $# -ne 1 || -z $1 ]]
 then
   echo usage: $0 version