qa/radosgw_admin: remove acl test cases

qa/radosgw_admin: remove acl test cases

they were comparing the output of 'radosgw-admin policy' with the xml
output of boto2's get_acl() function, but boto3 doesn't expose the xml
response

'radosgw-admin policy' is just dumping the same output as our s3
GetObjectAcl api, so test coverage from s3-tests is sufficient for this

Signed-off-by: Casey Bodley <cbodley@redhat.com>
(cherry picked from commit 070945ff432aa4d97bbc474bee82af338e0c778b)
Fixes: https://tracker.ceph.com/issues/75225
Signed-off-by: Adam C. Emerson <aemerson@redhat.com>