rgw/qa: Run tests on multiple cloudtier config

rgw/qa: Run tests on multiple cloudtier config

Run cloudtier tests with parameter 'retain_head_object'
set to true and false.

However having multiple cloudtier storage classes in the same task
is increasing the transition time and resulting in spurious failures.
Hence until there is a consistent way of running the tests, without
having to depend on lc_debug_interval, disabled one of the config for
now.

Signed-off-by: Soumya Koduri <skoduri@redhat.com>