Move ICU from ART APEX to i18n APEX

It involves a change of boot class path to use core-icu4j
from i18n APEX.

Bug: 138994281
Test: device boots
Test: m build-art-target-tests
Test: CtsJniTestCases
Test: atest libnativeloader_test
Test: ./art/test/testrunner/run_build_test_target.py -j80 art-test
Test: art/build/apex/runtests.sh
Change-Id: I30fc3735be760cba48856cd102852d2a6c796374
20 files changed