Reorganize the manifest.xml variants.

Things had evolved "organically" and become kind of a mess.  The new setup
has four toplevel manifests to choose from:

  openbox.xml: only the bits that are open sourced. (Enough to build an
    image.)
  no-drm.xml: openbox.xml plus proprietary (but non-drm-related) stuff.
    Useful for teams inside the company who don't need access to DRM bits.
  drm.xml: no-drm.xml plus DRM stuff (unfortunately including Chrome for
    now, since it ends up linking with DRM-restricted bits).
  release.xml: drm.xml plus bootloader source code, needed for code signing.

default.xml currently just points at drm.xml.  In the public repo, it'll
point to openbox.xml instead.

You can choose a manifest using the -m option to 'repo init' (which it's
safe to re-run even after checking out a repo).  For example:

  repo init -m release.xml
  repo sync -n

We also reorganize the actual packages into public, private, and
drm-restricted include files.  Before, drm-restricted was separate, but
public and private were mixed together (we used a separate branch to delete
the 'private' stuff before pushing publically), which was a maintenance
burden.  Plus, now it'll be obvious when someone makes a new package: they
have to put it in either public.xml or private.xml, making a conscious
decision.

b/33070819

Change-Id: Ibbba736f5adc06273d0565a22e079a8fc02453a1
11 files changed