Reduce memory usage by avoiding clones of ZoneInfoData objects

ZoneInfoData has become immutable and clones are not neccessary.
getTransitions() returns a clone of array as the @UnsupportedAppUsage
in ZoneInfo allows app to alter its internal values.

Remove the createCopy() @IntraCoreApi

Bug: 139480281
Test: atest CtsLibcoreTestCases
Change-Id: Icb4bb4cefe1595eb65e47a3a0bc9f1b2f640e339
4 files changed