Add libicuuc, libicui18n, libandroidicu, libpac to APEX

libandroidicu: Provides the stable C interface for other Android
components, except Apps. It's a stub of a subset of libicuuc and
libicui18n

libpac: It uses ICU4C C++ API, but has a stable C interface for
  libjni_pacprocessor. Thus, it should be moved into APEX.

Bug: 120659668
Bug: 121269980
Test: m droid
Test: art/build/apex/runtests.sh
Change-Id: I902c39b104a1678a046262e42efef07a60ee6558
diff --git a/CleanSpec.mk b/CleanSpec.mk
index e28ce2b..cd4e50a 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -53,6 +53,10 @@
 # Old Android Runtime APEX package, before the introduction of "release" and "debug" packages.
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/apex/com.android.runtime.apex)
 
+# Clean up ICU libraries moved to runtime apex
+$(call add-clean-step, rm -f $(PRODUCT_OUT)/system/lib*/libandroidicu.so)
+$(call add-clean-step, rm -f $(PRODUCT_OUT)/system/lib*/libpac.so)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************