chore: Update discovery artifacts (#1394)

## Deleted keys were detected in the following stable discovery artifacts:
bigquery v2 https://github.com/googleapis/google-api-python-client/commit/73965daab29cd6ae78004ede62f8c6c80f5587a3

## Discovery Artifact Change Summary:
feat(bigquery): update the api https://github.com/googleapis/google-api-python-client/commit/73965daab29cd6ae78004ede62f8c6c80f5587a3
feat(realtimebidding): update the api https://github.com/googleapis/google-api-python-client/commit/34d5d2606070b0c6fef053d6b88a65be085227b5
diff --git a/docs/dyn/realtimebidding_v1.bidders.creatives.html b/docs/dyn/realtimebidding_v1.bidders.creatives.html
index cd463e3..e42ed5c 100644
--- a/docs/dyn/realtimebidding_v1.bidders.creatives.html
+++ b/docs/dyn/realtimebidding_v1.bidders.creatives.html
@@ -516,6 +516,7 @@
         "priceDisplayText": "A String", # The price of the promoted app including currency info.
         "starRating": 3.14, # The app rating in the app store. Must be in the range [0-5].
         "videoUrl": "A String", # The URL to fetch a native video ad.
+        "videoVastXml": "A String", # The contents of a VAST document for a native video ad.
       },
       "restrictedCategories": [ # All restricted categories for the ads that may be shown from this creative.
         "A String",