Expose four ICU fields from version 66.0.1

This CL exposes four previously temporarily hidden fields which was done
to avoid merge conflits in downstream branches:

 * android.icu.lang.UCharacter$UnicodeBlock#CHORASMIAN
 * android.icu.lang.UCharacter$UnicodeBlock#CJK_UNIFIED_IDEOGRAPHS_EXTENSION_G
 * android.icu.lang.UCharacter$UnicodeBlock#DIVES_AKURU
 * android.icu.util.VersionInfo#UNICODE_13_0

Bug: 135752089
Test: m update-api
Change-Id: I5b3fec8edd6e990e839fbb8dfd93196cf60506c4
Merged-In: I5b3fec8edd6e990e839fbb8dfd93196cf60506c4