Revert "Fixes broken ACL removal in uninstall hook."

This reverts commit 5dce20c6bea43e0679245d70fcf5dc199d4e7dad.
Revert "Temporarily skips broken ExhibitBuilder-predicated tests."

This reverts commit c41aecae503f2d8a9e905aee14024beb2c7d9ab6.
Temporarily skips broken tests predicated on old ExhibitBuilder model.