phpunit tests: do not persist in providers
Provider functions are executed even if the test was not run, i.e. the
clean-up that the test performs one it is missing in this cases.
See https://github.com/sebastianbergmann/phpunit/issues/2007
Bug: T200693
Change-Id: I5ab768bc4fba2a325c2e386d25fcb6f4554152e8