Change the CountryZonesFinder API for picker

The UI picker will need more information now that there
is metadata associated with TimeZoneMapping. Rather than
return just the matchng ISO codes, return all matching
CountryTimeZone objects (usually 1) so the client can
do its own filtering as needed.

Bug: 73922616
Test: CTS: run cts -m CtsLibcoreTestCases
Change-Id: I51d9de37cdab84ce1c24921fa60a84af74b12e1a
2 files changed