Include ICU4C cc_library_headers instead of a directory

It includes the headers not in the directory, e.g. uconfig_local.h.
It may add more restriction during the build time,
but no runtime difference is expected.

Also, add ANDROID_LINK_SHARED_ICU4C flag to avoid
the new build-time error, since ART is allowed to link directly
to libicuuc.

Bug: 117094880
Test: m
Change-Id: I029532d6738aa6ade4f8f92c5a65f1a15e9de25f