Provide support for preparing tests with prebuilt_apis

Adds general support for generating a set of prebuilt apis for a set of
releases and modules. Plus some wrappers for common use cases.

This temporarily will delete any existing conflicting files and replace
them so that it can be used in tests without first removing
javaMockFS(). The future update that removes javaMockFS() will also
remove that workaround.

Bug: 182638834
Test: m nothing
Change-Id: If4e2118f2384b9866cf3f85a5afec1e2e4f9ac95