Move API providing modules from bp2build to api_bp2build workspace

The module types in scope are
1. ndk_library
2. ndk_headers, versioned_ndk_headers
3. api_domain

These modules will no longer generate Bazel targets in bp2build
workspace. A new soong mode `api_bp2build` will be used to generate API
specific targets in a separate Bazel workspace at out/soong/api_bp2build

Test: go test ./bp2build

Change-Id: I01d06b6d8b8364c0d56d6d3f07f8f8bf21db31d7