DO NOT MERGE Cherry-pick: ICU-20536 Japanese era Reiwa support in ICU4J 60

Cherry-pick https://github.com/unicode-org/icu/commit/223d4fb7e69b924db0e55e29162b8673bf1bb7ad

Update android_icu4j by running tools/srcgen/generate_android_icu4j.sh

Bug: 131312444
Test: CtsIcuTestCases
Test: CtsLibcoreTestCases
Test: CtsLibcoreOjTestCases
Merged-In: I6c1190c364176977e6aed8fda18e63f4cc8df667
Merged-In: Ifb7ba4f2951a40ab0350eb1c2cf9f94cc89cba13
Change-Id: Ifb7ba4f2951a40ab0350eb1c2cf9f94cc89cba13
(cherry picked from commit d426057c4373a48f9f65e8781a74c9789e492d3d)
7 files changed