Add ICU.addLikelySubtags(Locale).

We don't need a replacement for ICU.getScript(String),
Locale.getScript() can be used instead. The old definition
of the function has been left public for the support library
to use (though we could remove it if we modify the support lib).

Note that addLikelySubtag returns a String that's language tag
like, but uses underscores instead of hyphens to separate
subtags.

bug: 15876704

(cherry picked from commit 9c4462b3d88a36c92d23d4274195e4a7f7a372e5)

Change-Id: I3d2896a94c983e636523664315d09c93839dd9ae
2 files changed