fix: catalog defaults for scc evidence type (#588)

Author: huayuenh

ibm_catalog.json

@@ -1925,7 +1925,7 @@
                         {
                             "key": "scc_evidence_locker_type",
                             "type": "string",
-                            "default_value": "true",
+                            "default_value": "",
                             "description": "Allowable values are `evidence-repo` and `evidence-bucket`. If left unset, the SCC tool will behave as if `evidence-repo` has been set and will use the evidence repository configured in the toolchain. If the COS tool has been enabled, then the bucket name in `cos_bucket_name` will be provided to the SCC tool and `evidence-bucket` will be set. To override this behavior, explicitly set `scc_evidence_locker_type`.",
                             "required": false
                         },
@@ -4122,7 +4122,7 @@
                         {
                             "key": "scc_evidence_locker_type",
                             "type": "string",
-                            "default_value": "true",
+                            "default_value": "",
                             "description": "Allowable values are `evidence-repo` and `evidence-bucket`. If left unset, the SCC tool will behave as if `evidence-repo` has been set and will use the evidence repository configured in the toolchain. If the COS tool has been enabled, then the bucket name in `cos_bucket_name` will be provided to the SCC tool and `evidence-bucket` will be set. To override this behavior, explicitly set `scc_evidence_locker_type`.",
                             "required": false
                         },