chore: Update discovery artifacts (#1396)

## Discovery Artifact Change Summary:
feat(dialogflow): update the api https://github.com/googleapis/google-api-python-client/commit/f7b0ebc0047427b3633480999ed28e0f37fa77f1
feat(sasportal): update the api https://github.com/googleapis/google-api-python-client/commit/ca30eddc3d583c1851cc2f70f37c1d9f81f4342f
feat(youtube): update the api https://github.com/googleapis/google-api-python-client/commit/981cfb0ae51df0d2f48152bb74f79840ca19727a
diff --git a/googleapiclient/discovery_cache/documents/bigtableadmin.v2.json b/googleapiclient/discovery_cache/documents/bigtableadmin.v2.json
index d20fa69..70b4675 100644
--- a/googleapiclient/discovery_cache/documents/bigtableadmin.v2.json
+++ b/googleapiclient/discovery_cache/documents/bigtableadmin.v2.json
@@ -1619,7 +1619,7 @@
                   ]
                 },
                 "restore": {
-                  "description": "Create a new table by restoring from a completed backup. The new table must be in the same instance as the instance containing the backup. The returned table long-running operation can be used to track the progress of the operation, and to cancel it. The metadata field type is RestoreTableMetadata. The response type is Table, if successful.",
+                  "description": "Create a new table by restoring from a completed backup. The new table must be in the same project as the instance containing the backup. The returned table long-running operation can be used to track the progress of the operation, and to cancel it. The metadata field type is RestoreTableMetadata. The response type is Table, if successful.",
                   "flatPath": "v2/projects/{projectsId}/instances/{instancesId}/tables:restore",
                   "httpMethod": "POST",
                   "id": "bigtableadmin.projects.instances.tables.restore",
@@ -1628,7 +1628,7 @@
                   ],
                   "parameters": {
                     "parent": {
-                      "description": "Required. The name of the instance in which to create the restored table. This instance must be the parent of the source backup. Values are of the form `projects//instances/`.",
+                      "description": "Required. The name of the instance in which to create the restored table. This instance must be in the same project as the source backup. Values are of the form `projects//instances/`.",
                       "location": "path",
                       "pattern": "^projects/[^/]+/instances/[^/]+$",
                       "required": true,
@@ -1803,7 +1803,7 @@
       }
     }
   },
-  "revision": "20210504",
+  "revision": "20210513",
   "rootUrl": "https://bigtableadmin.googleapis.com/",
   "schemas": {
     "AppProfile": {