This changes:
- Add assertions for write_affinity values in load_app tests
- Add a test case that policy override read_affinity default by timing
strategy
- Avoid 'scope' but it's 'label'
Related-Change: I3f718f425f525baa80045ba067950c752bcaaefc
Change-Id: Ia8262490895d60da345f3679fc53653b2c2a2b3e