Add limit-tenants-to-placement-aggregate,
placement-aggregate-required-for-tenants and
enable-isolated-aggregate-filtering options.
Resolved Conflicts:
config.yaml
Closes-Bug: #1920982
Change-Id: Ibbb0e412d1a821cdb56e447ca88b91afca50c8c6
(cherry picked from commit 6c1efee2d0)