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

從 zoneinfo 模組的平台特定路徑偵測開始，並將 Android 與現有的 Windows fallback 進行比較。驗證相關的 Android 系統路徑，並新增測試以顯示會使用可用的系統 IANA 資料，而不是要求安裝 PyPI 的 tzdata 套件。