Simplify the preparation of an AOSP-like tree.

Some projects aren't in the base manifest any more and
don't need to be deleted any more.

Some projects are expected to be in AOSP and don't need
to be handled like proprietary projects.

Also add manta back.

Bug:4295425
Change-Id: I1e0c1c95c4943f9684efd3cb2a877f23c5d9fb7d
1 file changed