doc changes for image renaming.

doc changes for image renaming.

Changes:
- Global replace of image names with post-rework names.
- .rootfs image name suffix added to locally built image filenames.
- Image list updated in a couple of places to match conf-notes.txt
  update that has been submitted for meta-agl-core.

Bug-AGL: SPEC-5138

Signed-off-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I437f1e32078972ead2d1156686c54475e87bebaf
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/documentation/+/29928