Add 2 APIs in ExtendedTimeZoneNames and ExtendedTimeZone

Bug: 139480281
Test: treehugger
Test: CtsLibcoreTestCases
Test: CtsLibcoreOjTestCases
Test: atest libcore/luni/src/test/java/libcore/java/text/SimpleDateFormatTest.java
Test: atest libcore/luni/src/test/java/libcore/java/time/zone/IcuZoneRulesProviderTest.java
Change-Id: I282eea13928d39f7f90cdffa1820815ea337741c
3 files changed