Merge changes from topic \'icu_cp_catchup\' am: f6aabd95
am: 2b44297f
* commit '2b44297f':
Track external/icu API changes for factory registration
ICU4J: Hide constants that can change between releases
Remove RawCollationKey/ByteArrayWrapper from the public API
Change-Id: I485a59fa5a565d6916c9eed1e03dce3d01145a4e