Make probe tests work when policy-0 is EC
Make probe tests work when policy-0 is EC

test_object_metadata_replication requires a replicated policy. We even
have it subclass ReplProbeTest, but then we hardcoded the policy index!
Stop doing that.

Change-Id: I8871cc0beceb0909abaf59babe40c3cafbcd0cc9

openstack/swift,swiftstack/swift,psachin/swift,notmyname/swift,matthewoliver/swift,psachin/swift,clayg/swift,psachin/swift,smerritt/swift,swiftstack/swift,openstack/swift,nadeemsyed/swift,openstack/swift,smerritt/swift,clayg/swift,clayg/swift,redbo/swift,psachin/swift,matthewoliver/swift,notmyname/swift,matthewoliver/swift,notmyname/swift,nadeemsyed/swift,tipabu/swift,smerritt/swift,tipabu/swift,nadeemsyed/swift,redbo/swift,matthewoliver/swift,notmyname/swift,tipabu/swift,openstack/swift,nadeemsyed/swift,tipabu/swift,swiftstack/swift,clayg/swift,smerritt/swift