Make arm64 test script comaptable with old versions of gsutil.

NOTRY=true
R=borenet@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/183883020

git-svn-id: http://skia.googlecode.com/svn/trunk@13668 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/platform_tools/barelinux/bin/arm64_download b/platform_tools/barelinux/bin/arm64_download
index 598ee89..5bb44ec 100755
--- a/platform_tools/barelinux/bin/arm64_download
+++ b/platform_tools/barelinux/bin/arm64_download
@@ -45,7 +45,7 @@
     local gurl="$1"
     local file="$2"
     if ! [ -f "$file" ] || \
-        [ "$(gsutil stat "$gurl" | sed -n 's/\W*Hash (md5):\W*//p')" \
+        [ "$(gsutil ls -L "$gurl" | sed -n 's/\W*Hash (md5):\W*//p')" \
         != "$(md5sum < "$file" | sed 's/\W*-//')" ] ; then
         try gsutil cp "$gurl" "$file" || return
     fi