[build] Migrate to new package templates

Previously I thought we were going to delete //third_party/re2, but
there was a request to delay that change. In order to respect this
request without delaying the package() deprecation (almost done!) I'm
sending this migration change.

Change-Id: I8ba512630d630b634abb5ca7ff33f52987bcf7c6
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/re2/+/523620
Reviewed-by: Tom Bergan <tombergan@google.com>
1 file changed