[RFR] [8u] 8228469: (tz) Upgrade time-zone data to tzdata2019b

[Martin Buchholz]

At Google we try to keep our internal JDK's tzdata updated within a week or
so of an IANA tzdata release,
so we are already using tzdata2019c, and I recommend backporting that for
your jdk8u (in rearguard!).
But there are also risks when simply replacing upstream tzdata files, e.g.
we've run into
https://bugs.openjdk.java.net/browse/JDK-8226704
<https://bugs.openjdk.java.net/browse/JDK-8226704?filter=25118>
but tzdata2019c looks pitfall-free.