android: Fix CanonicalCookie same_site field

This field became an enum in r381201, but the java side was never
updated. Update java side to int instead.

Also update the format:
* Add an explicit version number that's just a date
* Explicitly encode the length so don't need EOF

Note the cookies can never persist across app updates, so no
need for any migration logic.

BUG=459154

Review-Url: https://codereview.chromium.org/1894213003
Cr-Commit-Position: refs/heads/master@{#390655}
5 files changed