Add support for Android to use old Olson IDs

IANA's tzdb 2020a update raised the possibility of Android continuing to
use old IDs. The tooling deliberately fails when Android isn't using
the same IDs as IANA's data. This tooling update has been prepared as
insurance in case Android needs to use old IDs in future. The existing
behavior (to error if a different ID from the IANA ID has been used)
has been retained, but with an override using "aliasId" in the
countryzones.txt.

Bug: 155738410
Test: atest --host tzlookup_generator_tests
Test: Ran the tool manually and inspected
Change-Id: I9fc5738d573d8cfe0e32a668a22eb40c49c56e82
7 files changed