DO NOT MERGE Fix tests which relied on Pacific/Apia DST offset [S CTS]

tzdata module prebuilts were updated to 2021a1 (2021b) in ag/16249425
and ag/16282952 enabled them. That caused failures in tests which
expected explicit offset in certain time zones.

java.util.TimeZone APIs allow to check offsets on specifc time, but
DateFormatSymbols always returns data as of now. So I've changed them to
be consistent with java.util.TimeZone.

Bug: 201301255
Bug: 204279800
Bug: 211073707

Test: atest luni/src/test/java/libcore/java/test/
Test: atest luni/src/test/java/libcore/java/util/

Change-Id: I9e13e6c4552697957f8eb3e3b0327fe7d321bef9
Merged-In: I9e13e6c4552697957f8eb3e3b0327fe7d321bef9
2 files changed