Change tzdata release to use rearguard data

Description

Current tzdata build script uses the stock tzdata files, with local override (icuzones).
ICU TC prefers to use rearguard data. Update the build script, remove some local override rules in icuzones.

Assignee

Yoshito Umaoka

Reporter

Yoshito Umaoka

Components

Labels

None

Reviewer

None

Priority

critical

Time Needed

None

Fix versions

Configure