The rules are updated to the latest UAX #29, with tailorings based on
the font in use: we can now use the clustering information
calculated by Layout, so we will only disallow a grapheme break if an
emoji ligature is actually formed.
Test: Unit tests have been updated and pass.
Bug: 30917298
Bug: 34211654
Change-Id: Idc0ef9f1f4f45dc45a50ed69e45c43ebfaea0306