orchestrator: Add nsjail support

This change adds nsjail support, runs .inner_build inside of an nsjail,
and runs ninja inside of an nsjail for the outer tree (with all inner
tree nsjails merged).

The latest changes to the interogate step have been incorporated in
inner_build_demo.py

Bug: b/239046008
Test: unit tests, manual run
Change-Id: I8ecd1c88e56807bc2f4b956e8f81e73f461e8e24
18 files changed
tree: ae256c4d62ef5e8a8454749ea0a0a05f8a3207f0
  1. core/
  2. demo/
  3. inner_build/
  4. multitree_combos/
  5. ninja/
  6. test_workspace/
  7. README