[8u] RFR: JDK-8274407: (tz) Update Timezone Data to 2021c

[Dmitry Cherepanov]

JBS: https://bugs.openjdk.java.net/browse/JDK-8274407
Webrev: http://cr.openjdk.java.net/~dcherepanov/openjdk8u/8274407/webrev.01/

Please review the update to tzdata2021c
  * updated manually from the rearguard version (tzdata2021c-rearguard.tar.gz generated by `cd tzdb-2021c && make rearguard_tarballs`)
  * backported the diff for ZoneInfoFile.java and TimeZoneTest.java (applied cleanly except the bug id in the test)
  * updated the copy of the timezone data that is in the test folder

Testing: tests for sun.util.calendar and java.time.test passed.

Thanks

Dmitry