Replace tearDown with addCleanup - Part 3

Replace tearDown with addCleanup in some cinder unit tests.

Infra team has indicated that tearDown should not be used and should
be replaced with addCleanup in all places.

Implements blueprint replace-teardown-with-addcleanup

Change-Id: I8469ffb5c896d40f9979cd6d1f8da81be763ec14
Merge "Replace tearDown with addCleanup - Part 3"