Use ICU in libandroidicu

libicuuc and libicui18n are moved into APEX, but
they have no stable ABI due to the version suffix.

Use libandroidicu which provides stable symbol.
See http://go/apex-stable-icu4c-interface for the design.

Bug: 117094880
Test: m checkbuild
Change-Id: Iab88307452d9467ddebc0d4dfc5a4799ff54324f