We plan to switch to devstack-gate for fullstack job, and it revokes
direct sudo calls before executing tests, so we can't rely on sudo
working anymore.
This also moves functional-testing.filters to a more generic filename
(testing.filters) because the filters are now deployed and used by
fullstack target too.
Related-Bug: #1557168
Related-Bug: #1693689
Change-Id: I1718ea51836adbb8ef8dea79822a722dcf111127