Complete code reviews

Nag all the reviewers to finish reviewing the code and change the status of bugs.

Check in serialization compatibility test data

ICU4J unit test contains serialization compatibility test cases. When a new reference version is released, we build serialized object data with the version and use it for future testing.

  1. Run "ant serialTestData" at ICU4J root directory
  2. The target generates test data and runs some serialization test cases.
  3. Once you confirm the test runs clean, copy out/serialTestData/ICU_<version> to main/tests/core/src/com/ibm/icu/dev/test/serializable/data/ICU_<version>.