Revert "Remove system images"

This reverts commit d8c4ab6ecbca7f7ae0504a42abd836f962077607.
Reason: Tests infra currently needs this

Bug: 390730574
Change-Id: Ia53c0b55c25df0d65693a4995691d99b3e99600b
300 files changed
tree: fe8820e77318040de206aaf22f53d63204800211
  1. darwin/
  2. generic/
  3. linux/
  4. windows/
  5. README.TXT
  6. update-emu-prebuilts.sh