Avoid tearing down process groups twice.

The second removal always triggers a warning.

Change-Id: Ieafa8374dbffdaff0d576de004a688cae6f8ac18
Remove some crufty "core" tests.

nobody runs these, and these things are well tested elsewhere
and a part of CTS.

Change-Id: I1ec00f2a085fc82f902f538ace692ac989ca03df
Merge "Remove some crufty "core" tests."
Merge "Avoid tearing down process groups twice."