Provide Android SDK via runtime classpath

[xian]

Create new artifacts containing versioned SDK code and data for Robolectric sandboxes, multiple of which can be safely added to the runtime classpath for Robolectric tests without side effects.

• [ ] android-all repackaging, contents
• [ ] new artifact naming, home
• [ ] upload new artifacts
• [ ] new artifact including all latest SDK versions
• [ ] remove dead DependencyResolver, robolectric-deps.properties et al.
• [ ] document change for other build systems

Fixes #3452