feat(bigquery): update the api

#### bigquery:v2

The following keys were deleted:
- schemas.QueryResponse.properties.sessionInfoTemplate.$ref (Total Keys: 1)

The following keys were added:
- schemas.QueryResponse.properties.sessionInfo.$ref (Total Keys: 1)

docs/dyn/bigquery_v2.jobs.html

@@ -3421,7 +3421,7 @@ <h3>Method Details</h3>
       },
     ],
   },
-  &quot;sessionInfoTemplate&quot;: { # [Output-only] [Preview] Information of the session if this job is part of one.
+  &quot;sessionInfo&quot;: { # [Output-only] [Preview] Information of the session if this job is part of one.
     &quot;sessionId&quot;: &quot;A String&quot;, # [Output-only] // [Preview] Id of the session.
   },
   &quot;totalBytesProcessed&quot;: &quot;A String&quot;, # The total number of bytes processed for this query. If this query was a dry run, this is the number of bytes that would be processed if the query were run.

googleapiclient/discovery_cache/documents/bigquery.v2.json

@@ -1683,7 +1683,7 @@
       }
     }
   },
-  "revision": "20210813",
+  "revision": "20210819",
   "rootUrl": "https://bigquery.googleapis.com/",
   "schemas": {
     "AggregateClassificationMetrics": {
@@ -4967,7 +4967,7 @@
           "$ref": "TableSchema",
           "description": "The schema of the results. Present only when the query completes successfully."
         },
-        "sessionInfoTemplate": {
+        "sessionInfo": {
           "$ref": "SessionInfo",
           "description": "[Output-only] [Preview] Information of the session if this job is part of one."
         },