Add a copy of api-versions.xml in prebuilts DO NOT MERGE

This CL adds a copy of api-versions.xml from the last release of
platform tools (25.0.3). This file will be included in a few more
releases of the platform tools, but will eventually be moved to
either be part of Studio or of the platform itself.

Test: N/A
Change-Id: Ibcd85249003552b52544997782c68fc5cb784b3e
2 files changed