Use system zoneinfo data on Android

Feature or enhancement

Proposal:

The zoneinfo module can load time zone information from the common IANA format: one directory per continent, containing one file per city. These files can come from one of two sources:

• The operating system in of the following paths: /usr/share/zoneinfo:/usr/lib/zoneinfo:/usr/share/lib/zoneinfo:/etc/zoneinfo.
• The tzdata package on PyPI.

None of the well-known paths exist on Android, so the best approach on Android is currently the same as on Windows – use the tzdata package from PyPI.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

从 zoneinfo 模块的平台特定路径检测开始，并将 Android 与现有的 Windows fallback 进行比较。验证相关的 Android 系统路径，并添加测试以表明会使用可用的系统 IANA 数据，而不是要求安装 PyPI 的 tzdata 包。